#serious-discussion

1 messages · Page 147 of 1

granite bridge
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anyways if you divide by n+1 you can have nonzero numbers multiply to zero

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and if you don't then the product doesn't work

gusty pelican
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I'm not saying that such an example doesn't exist but is there a way we can find that example?

granite bridge
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yes

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(1, -1, 1, -1, ...)*(1, 1, 1, 1, ...)

gusty pelican
granite bridge
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no it's not

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look at term number two

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(1 * 1) + (1 * -1) + (1 * 1) = 1

gusty pelican
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no

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on the second term there you missed a -

granite bridge
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where does the second - come from??

gusty pelican
granite bridge
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don't use a for both sequences

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it's a_0 * b_2 + a_1 * b_1 + a_2 * b_0

gusty pelican
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wait

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wait

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you're right

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I was stupid

granite bridge
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b_1 = 1, a_1 = -1

gusty pelican
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uh

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hmm you have a point then

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sorry for that

granite bridge
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lol no worries

neat lintel
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why discussy 2 more active than discussy 1

granite bridge
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we are discussying

neat lintel
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quit it.

alpine verge
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Maybe its time to abandon ship and treat {N-->Q}/{(a,b) | a-b is cauchy} in a vector space setting.

We will not be able to define the product without it being nilpotent, or having the unit be equal to 0.

granite bridge
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however it's quite easy to prove that when we restrict out view to cauchy sequences it is the same as component-wise multiplication (under our equivalence relation where their difference is cauchy)

gusty pelican
neat lintel
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not very discussy of you

granite bridge
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it could probably be an algebra

alpine verge
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yeah.

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That would allow us to exploit the order of N, otherwise it would go unused except for the cauchy sequences.

granite bridge
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yeah

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but in which case, the cauchy or component-wise product wouldn't make a difference

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i get the feeling that there's not a nice choice of product which makes this into a field though

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so we're probably gonna end up with nonzero elements multiplying to zero regardless

alpine verge
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yeah.

gusty pelican
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well rip multiplication I guess

granite bridge
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ill be back if/when i do

gusty pelican
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btw there's no point of extending Q to R since I'm pretty sure you can construct an "equivalent" N -> Q sequence for every N -> R sequence

alpine verge
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yeah.

gusty pelican
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in fact technically we could probably go from N -> {a/2^b: a, b in N} but we don't have to go that far. I like Q more anyway

alpine verge
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yeah

gusty pelican
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would it be possible to define integrals?

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it doesn't require multiplication, only like eqivalence class to natural number multiplication which we can define

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I guess it would be like a path integral or something

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though a straight one of course

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I feel like I'm missing something with the integral thing

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wait

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it requires multiplication

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oh shit

alpine verge
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If we want to define integrals of functions on {N-->Q}/{(a,b)|a-b is cauchy null sequence},
we need to know if the space is measurable

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I'd first treat {N-->Q}/{(a,b)|a-b is cauchy null sequence} as a vector space and see if we can find a basis.

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(in the absence of a product.)

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Interestingly (1,0,0,...),(0,1,0,...),(0,0,1,0,0,...) are not basis vectors, as they are equal to zero

gusty pelican
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huh
well if we are going down that route I guess we should start with that

alpine verge
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(1,1,1,1,1,1,1,...), (0,1,1,1,1,1,1,...), (0,0,1,1,1,1,1,1,...) ,...
would be a basis.

alpine verge
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shit you're right.

granite bridge
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not equal

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anyways the real problem is that a basis requires a finite set of them sum to any sequence

granite bridge
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you can't construct an explicit basis unfortunately

alpine verge
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what about bounded infinite linear combinations.

granite bridge
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as the existence of a basis depends upon the axiom of choice

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and the basis is gonna be the size of R i think

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or more

plain owl
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not more

alpine verge
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But if Q^omega has dimension omega, why do we need AC for a basis?

plain owl
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there are only R sequence

granite bridge
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lol you're right

granite bridge
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and the existence of a basis for R over Q requires the axiom of choice

alpine verge
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I'm confused. I mean for e.g. Q^omega we have this basis (1,0,0,0,...),(0,1,0,...), (0,0,1,0,0,...) without AC.

granite bridge
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it's not a basis

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how do you get (1, 1, 1, 1, ...)?

gusty pelican
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(remember you have to do a finite sum to get there)

alpine verge
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Then a basis is not what we are looking for.

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This finite sum stuff is flawed.

plain owl
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well if you have a topology you can define a schauder basis

alpine verge
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I dont think we have a topology. Lets just try to define a basis* ad-hoc.

granite bridge
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do we have an inner product?

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for orthonormal to make sense?

alpine verge
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nope.

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thats why I want to look for a basis*

granite bridge
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i dont think integrals are gonna work without a basis or inner product

solid snow
alpine verge
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yeah.

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Anyway, for our setting lets just define a (well-ordered) basis* as a mapping:
B: omega -> {omega-->Q}/{(a,b)|a-b is cauchy null sequence}
(the well-ordering is so we fix an order when we do the summation, in the square summable case this is order independent, but here its nots square summable.)

granite bridge
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how do we even define infinite sums on this space

alpine verge
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we do well-ordered sums and hopefully they converge. Otherwise idk.

granite bridge
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because the rationals aren't complete so we can't just take their limit

alpine verge
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whatever just take the metric completion IDC.

gusty pelican
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basically gettting the N to R sequence and then just getting a N to Q sequence

granite bridge
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you could but i don't think the concept of a basis that requires infinite vectors is very useful

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or like infinite sums, rather

alpine verge
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None of this is useful, but I think in this its the most elegant solution to arrive at some kind of "basis", for this setting.

neat lintel
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is a pad thats 420.4 x 2 Inches good for space cuz i wanna make some math vids and write on it

alpine verge
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We are explicitly dealing with unbounded infinite vecotrs.

neat lintel
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is it small

neat lintel
alpine verge
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So I think unbounded linear combinations are also "allowed" here.

granite bridge
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420.4 inches x 2 inches?

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i think that's like way too long

neat lintel
#

HUION H420X OSU Drawing Tablet Upgrade of Model 420,4 x 2 Inches OSU Tablet Graphics Digital Writing Pad with 8192 Levels Battery-Free Pen, Compatible with Chromebook, Mac, Windows, Android, Linux

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this is the thing on amazon

granite bridge
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it's 4 x 2 inches

neat lintel
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if u google it, it will show up

granite bridge
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not 420.4 x 2 inches

neat lintel
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hahahahahha

granite bridge
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if not i wanna see a pic of the like 30 foot long drawing tablet

neat lintel
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ohhh i didnt see the "model"

neat lintel
granite bridge
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idk use a ruler lol

neat lintel
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like is there good enough space to write

neat lintel
granite bridge
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as obvious as it sounds, if it's not a basis, it's not gonna be completely interchangeable with a basis

alpine verge
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In this I only want to consider (well-ordered, possibly unbounded) Schauder basis.
Maybe see if we can define an inner product or exterior algebra.

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But first I wanna find a "basis"

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Maybe (1,1,1,1,1,1,...), (0,1,0,1,0,1,0,1,0,1,0,...),(0,0,1,0,0,1,0,0,1,...),...

pliant prairie
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i had a question, i cant type it its long, any idea where i can find possible answers?

granite bridge
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nowhere if you can't type it

pliant prairie
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thanks

gusty pelican
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I'mma go to sleep
If you guys continue this conversation then I'll read the rest of it later
this was actually an a lot more interesting conversation than I thought it would be

frank sage
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What are radical axes

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I can not understand

urban berry
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hi

fierce scroll
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,calc sin 37

fathom swallowBOT
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The following error occured while calculating:
Error: Unexpected type of argument in function multiplyScalar (expected: number or Complex or BigNumber or Fraction or Unit or string or boolean, actual: function, index: 0)

stone ferry
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It's not a quotient

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and afaik it's not a tensor

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Let me give you the example of R_3,0,0

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it's a fairly simple one

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you have the vector space R^3, right?

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let e_1, e_2, e_3 be its basis

vale plover
stone ferry
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then the basis of $\mathbb R_{3,0,0}$ is:
$$1, e_1, e_2, e_3, e_1e_2, e_2e_3, e_3e_1, e_1e_2e_3$$

fathom swallowBOT
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MSC2020 47A15

tender tulip
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I think all I needed was that x^2 = Q(x) for Q(x) a quadratic form

stone ferry
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and you define a product (written with juxtaposition)

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sure

tender tulip
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So it’s $\frac{T(V)}{(v^2 - Q(v)}$

fathom swallowBOT
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Dyfunction Executive

stone ferry
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orthogonal vectors anticommute

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I'm not sure what T(V) is but I think I can guess. That probably works

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yeah it's the tensor algebra

stone ferry
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and I was wrong about both counts of it not being a tensor or a quotient

tender tulip
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Orthogonal in respect to Q(v + u) - Q(v) - Q(u)?

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geometric algebra over char 2 seems fucky and unimportant

stone ferry
tender tulip
stone ferry
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I don't think this is ever done outside R

tender tulip
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@jagged forge wallflower ass mf

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Probably for good reason

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Not much that it can be applied too

jagged forge
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i was going to say something pedantic but i am not sure if was actually true KEK

stone ferry
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doing it over C is useless because you can reduce it to something over R

stone ferry
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since C is a clifford algebra

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specifically R_0,1,0

jagged forge
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strictly speaking they're not tensors, but i think over dim =/= 2 you can represent them as tensors, idk

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err

tender tulip
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I mean

jagged forge
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char(K) =/= 2

tender tulip
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Tensor algebra sully

jagged forge
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yeah but quotients of tensor algebra

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not the same thing tho

tender tulip
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Any element of an algebra can be thought of cosets of tensors in that regard

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Fair enough

tender tulip
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Because I can say my finger is an appendage but that means fuck all shit in flipping you off

jagged forge
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i think it was you could define the multiplication in terms of tensors

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but i actually think maybe i was reading about something else like the symmetric algebra or something

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idk

tender tulip
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I don’t really get what you’re getting at but I don’t know tensors all too well aside from their construction and definition as a tensor product pretty much

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So when I see contravariant and covariant I assume by default that’s just related to base changes on the regular vs dual

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for finite dim spaces

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And it’s a tensor product of the vector space and it’s dual so many times

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I do not know the applications or how it’s used though in that sense

jagged forge
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the tl;dr is quotients of the tensor algebra are not necessarily subalgebras of the tensor algebra, but in some cases i read sometimes they can be in characteristic not 2

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for some specific quotients

tender tulip
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Eh I guess

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Probably some exotic examples of little use I assume

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I know tensors are used in physics but idk how outside of the exterior algebra

jagged forge
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ah it was the exterior algebra where i read that

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in characteristic not 2 the exterior algebra can be identified with antisymmetric tensors

tender tulip
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What do you mean

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By antisymmetric tensors

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I don’t get shit like “stress tensors” or any christoffel shit

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Like I assume there is a MUCH simpler definition with tangent spaces and tensor powers of it

jagged forge
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here's a simple example of an antisymmetric tensor

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ab^T - ba^T

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which is uhhhh

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an element of V \otimes V

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the idea is if you swap any two positions you get the negative

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so if you swap the first factor with the second you get ba^T - ab^T

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so...... basically that but with arbitrary tensor products

tender tulip
jagged forge
fathom swallowBOT
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suremark MSC2020 60G40

jagged forge
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since the transpose is kinda vague here

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but it's kind of the same idea, if you pretend x is a dual vector and that a^T x = x(a) (the dual pairing) and not the dot product

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ab^T x = a * x(b) gives you a map from V* -> V

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which is the same as V x V by duality, or the same as a map V* x V* -> K

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i dont think im explaining this well opencry

tender tulip
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The transpose confused the actual fuck o ur big me

tender tulip
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The fuck is a dual pairing

jagged forge
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you know, the natural map between V x V* -> K

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which exists and is basis independent

tender tulip
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so the valuation?

jagged forge
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uhhhh… yes

tender tulip
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Ah okay

jagged forge
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i’m gonna assume we’re talking about the same thing lol

tender tulip
jagged forge
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an element of the dual

tender tulip
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V* and V aren’t naturally isomorphic I think though

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For finite dim

jagged forge
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nope!

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aren’t they just straight up not iso at all in infinite dim

tender tulip
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One’s a direct sum over the field, the other a direct product

jagged forge
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ohh….

tender tulip
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So they correspond for finite bases lol, that’s my justification

jagged forge
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direct product in infinite dim yikes

fair mural
stone ferry
tender tulip
jagged forge
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i just thought the direct product is like, badly behaved in a number of ways a lot of the time

tender tulip
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not visualize I mean

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Explain

neat lintel
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wassup guys

jagged forge
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yeah ik what it is. well actually i haven’t studied category theory so maybe i don’t KEK

tender tulip
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Essentially V is a direct sum indexed by the basis since every element is some sum of a finite subset of the basis. However to look at the dual, you consider maps to V. Which are infinite product instead, by looking at the image of each basis vector

stone ferry
jagged forge
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ah that makes sense actually

tender tulip
stone ferry
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I'm sorry I'm not category pilled enough

tender tulip
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This isn’t really a category theory level concept

stone ferry
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I wanted to do algebra and then I got sucked into functional analysis

tender tulip
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If you know direct sums and products of abelian groups

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It is literally that

jagged forge
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well naturally isomorphic (which he was asking about) definitely is tho

stone ferry
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I meant natural isomorphism

tender tulip
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I don’t really remember the definition of natural very well

stone ferry
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V* and V are about as isomorphic as you can get in my mind

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for finite dimensions

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or any hilbert space

tender tulip
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Yeah

tender tulip
tender tulip
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Or cotangent spaces

azure frigate
#

hi guys just a quick question. pi/4 * d^2 is an area of a circle right?

tender tulip
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Idk how they are used and the symbols are scary

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Yes

stone ferry
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Physics notation is fucked up

azure frigate
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oh i thought it was pi * r^2

tender tulip
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I tried reading about some thing for physics and got jumpscared by something called Christoffel symbols and shit

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Also the metric tensor being called a fucking tensor and not just a form

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It’s just a bit confusing

tender tulip
stone ferry
azure frigate
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lol the professor fucked me up with one a nanometer question

tender tulip
azure frigate
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fluid dynamics xD

tender tulip
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But I’m not going to call the inner product or dot product the “dot tensor”

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Gotta compute the cross tensor

jagged forge
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the fuck is a dot tensor

tender tulip
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IT ISN’T

stone ferry
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ew cross products

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(does not generalize)

jagged forge
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well to be fair it doesn’t really exist in general

tender tulip
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The dot product is technically (excessively nasally) a tensor

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It’s an element of (V x V)*

azure frigate
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thanks haha

rocky shuttle
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Well, call it the metric tensor then catshrug

tender tulip
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metric form

rocky shuttle
#

first fundamental form

stone ferry
#

I did think of a fucked up new linear algebra course structure idea

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topic 1: vector spaces

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topic 2: tensors

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topic 3: linear functionals

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topic 4: matrices

tender tulip
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No I'm pretty sure tensors and multilinear algebra are expected to magically appear in your head after one intro course of lin alg

rocky shuttle
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top(olog)ic(a) 1: vector spaces

rocky shuttle
#

what space

neat lintel
#

@burnt knot hey

burnt knot
#

Hi

neat lintel
#

look, I won't tell you I am perfect or even an expert

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but as I've spoken with you with logic

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I will continue in logic

burnt knot
#

Are you in uni rn?

neat lintel
#

if you don't like what you've done, leave it and go to another on

neat lintel
burnt knot
#

For pure math?

rocky shuttle
#

space is flat

neat lintel
burnt knot
#

Oh cool

neat lintel
#

don't just destory everything and run to what you love with no plan

#

if you don't have a good life now but I think it might be stable to some extent

rocky shuttle
#

you're moving along a geodesic in spacetime

burnt knot
#

Yeah its not horrible rn

neat lintel
# burnt knot Oh cool

Set dreams, goals, plans, ...etc and start work on it.

bear with what you do until you could give up upon it if you hate it

#

once you can give up upon it, do it but be sure you won't affect bad on yourself

neat lintel
burnt knot
#

Alright thank you!

neat lintel
#

my pleasure

burnt knot
#

Im just at a crossroad right now not knowing what to do

neat lintel
#

give yourself time and be alone and create who you want to be

#

and when I say create I mean it, because we don't find ourselves we create it

#

if you want to discuss anything, just hit me up my DMs are open and we could chat or even have VC about it

rocky shuttle
#

Spacetime can be curved, but the universe is flat, at least according to this: https://www.nobelprize.org/prizes/physics/2019/popular-information/

NobelPrize.org

The Nobel Prize in Physics 2019 was awarded "for contributions to our understanding of the evolution of the universe and Earth’s place in the cosmos" with one half to James Peebles "for theoretical discoveries in physical cosmology", the other half jointly to Michel Mayor and Didier Queloz "for the discovery of an exoplanet orbiting a solar-type...

#

Measurements of cosmic background radiation, as well as theoretical considerations, provided a clear answer – the universe is flat.

flint island
#

Flat essentially just means "as Euclidean as you're gonna get" (on large scales)

#

really though it means Minkowski (not Euclidean)

wet glacier
#

since this server is alot more busier then chem server can sm1 help me understand this table ? its a** chem question**

rocky shuttle
#

The organic chemistry tutor can

minor current
#

Hi

rocky shuttle
#

Hewwo

loud snow
#

Dont have to

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I was just gonna send to friend who is analytical chemist

wet glacier
loud snow
#

K

neat lintel
#

i think i’m over math 😭

#

biggest struggle

fresh comet
#

social sciences?

orchid badger
#

hey
the vector equation of line

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like
r(t) = a + at
(t is parameter)
like what you really mean by this

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a is a point on the line

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right
then why we have to add the point

unborn trellis
#

it's really r(t) = a + bt, where a and b are points

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a is the origin of the line, b is the direction

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You can think of it as the points in direction b shifted to a

neat lintel
#

It's cool if you think its cool

orchid badger
orchid badger
#

like I know it's from where the vector begins but still

neat lintel
austere merlin
#

erm guys there’s a problem…

neat lintel
#

a is like the transformation of the vector from the orgin

austere merlin
#

I forgot how to write a quadratic function in standard form

neat lintel
#

$f(x) = a(x-h)^2 + k$ something like that

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oh wait lmao

#

different thing

austere merlin
#

huh

#

y = 4(x - 2)^2 + 4

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wait how would I write that

neat lintel
austere merlin
#

y=4(x-2)(x-2)+4

neat lintel
#

continue

austere merlin
#

wait I’m going crazy

#

LOL

#

I know how to do this

#

tyyy

hardy grove
#

is learning calculus at grade 8 normal

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or am i a bit behind

neat lintel
forest vale
alpine kindle
rocky shuttle
placid finch
dark escarp
#

hello

hollow vessel
#

can someone help me with this crossword:
How prawns save $
6 letter word, starting with S and has M in the 5th position

hollow vessel
#

ty

#

Where subsistence-level farmers start to end up at their mouths
4 letter word with A as second letter and D as last letter

vocal vessel
#

That sentence doesn’t make sense to me.

#

At their months?

hollow vessel
#

wait

#

mb

#

mouts

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mouths

vocal vessel
#

Not clearer

#

Only thing I can think of with farming is “land” but I don’t get how they start at land and end up at their mouths

hollow vessel
#

i wrote yard but idk

vocal vessel
#

Yard to mouth? Hmm. Makes zero sense

#

Hand?

hollow vessel
#

ohhh

#

that make much more sense

#

but still idk

vocal vessel
#

🤷‍♂️

#

Unrelated. Thanks for playing.

hollow vessel
#

👌

vocal vessel
#

The shortest war in history lasted only 38 minutes. It was between Britain and Zanzibar on August 27, 1896.

#

Bananas are berries while strawberries are not.

#

Some cats are allergic to humans

#

No

formal pebble
#

hi

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so I'm just wondering..

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have you guys had heard about magic triangle

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the thing where each sum of the side of the triangle will be equal

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just wondering if there any ways or tricks to solve it aside from trial and errors?

high topaz
#

i also have a question: is there any method of predicting if the set of numbers at hand could actually be used to create that magic triangle

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or even more interesting how many magic triangles could we create with one set of numbers

pearl moth
#

what is a magic triangle nvm looked it up

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there are number-theoretic approaches to finding solutions, but for low orders exhaustive search is often easiest

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there aren't that many possibilities to consider

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for example, for order-3 you know the sum has to be at least 9 and at most 12 since 6+2+1 is 9 and 1+5+6 is 12

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for order-4 similarly you get at least 16 and at most 28

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i just found a paper that offers bounds for the sum on order 4 of 17 to 23 using a different argument

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and they provide a formual for the bounds that apparently works for any n

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although the paper is lacking in rigor: it sets forth formulas but rarely proves them

high topaz
#

why thank you... and can i have a link and see these myself

pearl moth
#

written by a 9th grader lol

#

stiull not bad for high school work

knotty sedge
#

guys

#

i have taken as an undertaking

#

the task of obtaining

#

every utm

#

and gtm book

fresh comet
#

ask @ripe needle to aid you

ripe needle
#

I have most of them via pdf lol

#

My physical collection is lang and stillwell

grizzled grove
#

But why you're collecting so many pdfs?

fervent pebble
#

free dissemination of information fr

alpine comet
#

what the fck is elliptic cohomology?

#

I feel like I'm a 9-year-old reading Rudin

knotty sedge
#

im obtaining them by purely legal means!!!! /j

meager sonnet
#

and using something called landweber exact functor theorem (LEFT) get a cohomology theory

alpine comet
#

I did not know about this

#

is there a one-to-one correspondence between homology and formal group law?

meager sonnet
#

no

#

only certain cohomology theories

#

Uhm

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I should start over

terse comet
#

🧊

meager sonnet
#

MU_* is isomorphic to the graded Lazard ring which is effectively a classifying ring for FGLs over R

#

so a formal group law over R is equivalently a graded ring homo. L -> R

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Using this iso this gives R the structure of a MU_* module

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And so we can take the extension of scalars

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$E(X) = MU_(X) \otimes_{MU_} R_*$

fathom swallowBOT
#

cofibrant woman

meager sonnet
#

Now we want E to be a cohomology theory and it's pretty easy to prove that it satisfies everything but Mayer-Vietoris

meager sonnet
#

Asking R to be flat over MU is really hard to do so LEFT gives sufficient conditions for this tensoring to preserve Meyer-Vietoris specifically

#

And elliptic cohomology defines a formal group law

#

I can't say much on that myself I'm not super familiar

#

There's also a theorem which says that this assignment of an elliptic curve to the multiplicative cohomology theory can lift through a map which first assigns an E_infty ring spectra to the curve

#

Then a map that takes the cohomology theory that spectra represents

#

This gives you an assignment of E_infty ring spectra to elliptic curves and you can take a homotopy limit of these over the moduli stack of elliptic curves

#

Combining the data of all the E_infty ring spectra for every elliptic curve into one E_infty ring spectra, which is called topological modular forms

vivid halo
#

Tfw sheaf of spectra

meager sonnet
#

Yeah

vivid halo
#

restrict to Tate curve
get KO[[q]]

meager sonnet
vivid halo
#

Yeah I mean this is cute and natural

meager sonnet
#

S^1 equivariant K-theory of free loop spaces tensored with Laurent series

#

Admittedly IDK much about Tate curves or anything but this is weird to me

#

IK there's some statement of all height 1 FGLs obeying <property> give either ordinary cohomology, K-theory, or are elliptic curve FGLs and give elliptic cohomology

vivid halo
#

Tate curve is the formal neighborhood of the point at infinity in M_ell

#

So it’s the formal neighborhood of the nodal cubic

#

The stuff you get when degenerating to the nodal cubic is very much height 1 stuff

orchid badger
#

ig this is going to be a very dumb question but still I want to ask
if I have a vector called 𝐚 which has some value in the x , y and z direction
but I break that down and writes the value as x , y and z
and scale them up by some quantity
will that still be a vector

vivid halo
vivid halo
#

It is such a shame that you can’t really play this game with higher rank formal groups

orchid badger
#

and any tips on doing vectors
cause I am watching a lot of theory and also attending my lectures
(first semester uni student)
but still sometimes struggle to do some basic vector question

plain owl
#

do you know what a vector space is

#

it looks like not

#

so that would be a good place to start

fresh comet
#

by what name am i supposed to refer to this discord server as in a conversation?

#

give me some names to call it lol

neat lintel
#

lol

#

are you gonna tell someone irl about it?

jagged forge
#

mathcord

fresh comet
#

not quite

neat lintel
#

when i'm on the server i call it lowmath

jagged forge
#

how dare u

neat lintel
#

when i'm complaining to my bf about something on it i just say "the math server"

fresh comet
#

yeah i call it the "global math (discord) server" if i ever mention it to my friends rn lol

#

i omit "discord" when im lazy

#

yes, i call it "global"

#

idk why

#

the name stuck for me lmao

#

maybe mathcord is better tbh

fresh comet
#

some of them are here too

neat lintel
fresh comet
#

but they dont often type

#

none of them are very into math i'd say

visual breach
#

How do you guys get to such advanced concepts, dealing with moduli stacks and K-theories

visual breach
#

It would take lots of time, right

vivid halo
#

it often takes a couple of years yeah

visual breach
#

Perhaps too late for me catscream

#

Would not going to reach there during my doctorage years

#

So excession reached there that fast? Woah.

visual breach
#

I wish there were a cure for my mathematical dumbness

neat lintel
visual breach
#

Textbooks cannot cure me of my slow learning speed

neat lintel
#

Yes they can

visual breach
#

Do you have experience in this?

orchid badger
#

those people who are studying mk and AI stuff
how important is vector for you

neat lintel
#

My knowledge says otherwise

#

Classes that you can pass by just attending the lectures are nice for an easy A, but you miss out on a lot that you could had learnt from the textbook

#

my discrete math class doesn't require a textbook and its so much easier than actually reading the book, but I'm 100% missing out on so much stuff because of it

rocky shuttle
#

Which math textbook?

visual breach
#

Pre-uni textbooks KEK

#

I'd say, depends.

tall minnow
#

you are still in pre-uni so you have time to fix that

#

learning habits develop as you go higher and you figure out eventually you need to read stuff properly instead of just winging it like in high school

pearl moth
neat lintel
#

hey does anybody here know like a list of all the math topics or lessons in the world and in order from easiest to hardest? i need the resource badly

solid snow
#

theres no such thing

glass peak
deep mango
#

Instead of interpreting this question completely literally like the last 2 ding dongs

glass peak
#

Rude

deep mango
#

(And has tons of lessons and problems on all of them)

final rivet
pearl moth
#

khan academy is a perfectly reasonable option for learning basic math

#

it's not perfect but it's free and readilyt accessible

#

and yes there is no canonical all-inclusive list of math topics, let alone one ordered by difficulty, in part because that's clearly at best a partial order and it's also extremely subjective

fresh comet
#

50 minute tests are too stressful

#

I feel like they shouldn’t be allowed lmao

pearl moth
#

yeah, should be either 49 or 51. even numbers of minutes are just wrong

neat lintel
#

anyone here that uses a WSL? I got bombarded with Zone.Identifier copies in all of my files for whatever the fuck and im trying to delete them bending_skull

neat lintel
neat lintel
pearl moth
neat lintel
pearl moth
#

oh you used edge

neat lintel
#

i actually didn't which makes it more peculiar

neat lintel
pearl moth
#

it's got to do with writing into the linux filespace from the windows side, apparently. i never do this so i don't run into it

neat lintel
#

was a bit worried tho because i had my hw due soon and i thought i had to manually delete each one bending_skull

neat lintel
pearl moth
#

the connector for the filespace access does not properly understand the request to open an alternative data stream, which is a feature that NTFS supoprts but the filesystem used by the linux emulation does not

pearl moth
#

where x is the windows drive letter. by default wsl mounts all of your windows drives in /mnt by drive letter

#

this also avoids bloating the linux-space file images

sacred furnace
#

i can never learn from videos tbh

#

i go out of my way to buy textbooks even if they're expensive even

neat lintel
sacred furnace
#

idk learning by video just doesn't do it for me

vivid halo
#

imagine buying textbooks in the current year instead of [redacted]

sacred furnace
#

i am very easily distracted even from things i actually like

#

i will see a shiny thing and go "oo shiny thing"

#

i have to actually put a sizeable distance between me and a distraction machine for me to actually learn

tall minnow
#

you are going to need to fix that because more likely than not you need to write latex notes while you learn / draft stuff etc.

#

I have embraced the distractions as I write my paper while listening to streams in the background. if I need to hugely focus I put on instrumental music

sacred furnace
#

uh

#

maybe i overstated my distractability

#

i should have said

#

i like doing it the way i do

#

honestly quite a few people find my methods to be weird

#

but it got me this far so

tall minnow
#

well some people prefer paper books and fountain pens

sacred furnace
tall minnow
#

what's your specialization btw

sacred furnace
#

nothing yet

#

my program is officially

#

applied math in life sciences

tall minnow
#

so analysis, optimization, statistics, numerical etc. ?

sacred furnace
#

i have to do a lot of numerical analysis

#

i have a numerical analysis exam in 4 days actually

tall minnow
#

I knew someone who entered PhD as an applied analyst and then switched to stochastic PDE research

#

well it depends on the department's flexibility as well

sacred furnace
tall minnow
#

I'm also slowly getting into stochastic myself. lots of things happening.

cunning plaza
#

I'm not yet at the phd level, so just curious on what you would recommend there

tall minnow
cunning plaza
tall minnow
vivid halo
#

Lyx is goofy

static stirrup
#

What Is the best argument for beginners to start in mathematics ? ( i study ICT so I would like to have topics that fall into that area)

old plover
#

dont want to step on anyone's convos in here. i'll be posting a mini discussion in #optimization

pearl moth
#

there's no convo in here to step on

foggy snow
#

Name some good books for integral calculus or whole calculus,which contains solved problems most

neat lintel
neat lintel
#

It's been a year since I've written this program and it finally stopped working.

#

hampter Time to spend a week rewriting

digital galleon
sonic sentinel
#

wtf do you mean we don't know if pi+e is rational

#

all this math and shit and we don't even know if pi and e are in a conspiracy

pearl moth
#

math is hard, what can we say

#

at least we know that sqrt(2) + sqrt(3) isn't rational!

alpine comet
tall minnow
#

they are irrational with probability 1

plain owl
#

well tbf, as an informal statement it's fine

#

just obviously it's either 1 or 0

tall minnow
#

rationality reduced by mod 1 to the torus equipped with the Haar measure

solar hawk
old plover
#

there's no convo in here to step on
well too late I guess. i dont want to copy and paste it. those with langrangian experience can check it out in #optimization . it feels like a long shot at this point

#

i have another engineer working on it (the general problem), i just wanted to try this approach myself to see where it got me (nowhere fast sofar)

#

bout to stop work for the day but i'll check back tomorrow or next week

wraith forum
#

here I am finding theorems on infinity craft

orchid path
solar hawk
#

ayo?

orchid path
#

fk

hallow maple
#

Anyone doing a level maths?

rapid yacht
#

Could someone help with stats pls

ocean harbor
tired harbor
ocean harbor
#

no

vernal token
shrewd ledge
#

Hello

neat lintel
# vernal token What's that

A browser game by neal.fun where you start with four basic elements and you can craft your way into practically infinite items or just script them in

stable sage
#

what row operation can i do to make A1,2 A1,3 and A2,3 all 0

1 + 1 + 1
0 + 1 + 2
0 + 0 + 8

#

only the diagonal elements need to be non zero

#

iam doing some gauss elemination thing

vernal token
#

A_1 -> A_1 - 1/8A_3

#

The next step you'll see

scenic pond
#

gonna find riemann hypothesis wish me good luck

scarlet lark
#

Does anyone know what happened to the STEM server?

ocean harbor
scarlet lark
#

frick!

#

I had about all my proofs in there.

#

Why did it get deleted?

loud snow
scarlet lark
#

I did.

#

Just the convesation were fun to read.

loud snow
#

Huh

#

O

#

Rip history

#

The logs are probably still out there

#

Might be able to ask discord

ionic glen
#

hi

neat lintel
deft prism
#

i like creamy penutbutter

ionic glen
#

...

ionic glen
#

w-what

mental stratus
#

crunchy is better

jagged forge
#

pika knows what’s up

lethal tree
#

bro guys

#

i thought my math was done in 2022 after my hsc

#

just realised

#

i have math in uni

#

fmd

tender tulip
#

Like crunchy peanut better is best if you just eat it straight

#

Creamy is better for adding it to shit or using it on a sandwich

#

In other words, crunchy peanut butter is gluttony

neat lintel
#

peanut butter is

ripe needle
#

Oh boy discussion-2 opencry

fresh comet
#

you cant be jailed for tax evasion if you never get caught

ripe needle
orchid badger
#

worst way to study maths-
remember the formula and solve qus
i mean thats worst than not studying maths

what you all say

ocean harbor
#

what

#

imo if you just sleep during the lesson and then when you get a hw/test or whatever, you don't know anything

#

but "remember the formula and solving questions" isn't that bad tho ded

strange garnet
#

yes you need to learn the formula. but just because you know the formula doesnt mean you'll understand it. there's so much more to a math problem then the formula. for some people (me) no matter if i barely know the formula or know the formula 100%, i need to ACTUALLY understand the problem. which is why i work better 1on1, peoples minds work differently. its always hard being in a classroom with 11 other people, they all understand it by the formula but im completely lost.

orchid badger
#

damn
you are right
fir me the concept is more important the remembering the formulla

atomic locust
#

gotta take the proof out for a few dates first

prime jasper
#

yall are fucking nerds

dire glen
#

hey hello

#

when i solve a system of equations i am looking for points that are a solution for both all the equations..

#

so if i have 1 equation like x+y+z = 4 this means all the points that when you take the dot (1,1,1)*(x,y,z) = 4

tacit magnet
#

Yes(?

dire glen
#

and if i have 2 equations the points xyz are further restricted.

#

is this finding an intersection between the 2 equations?

tacit magnet
#

Yeah

dire glen
#

could this be written equation1 ∩ equation2 ?

tacit magnet
#

Sure

dire glen
#

if i were to write this in code, this would correspond to "and" ?

river moon
#

an intersection between solution sets, not equations

dire glen
#

intersection between equations doesnt means anything right?

river moon
#

intersection is an operation between sets

dire glen
#

ok all makes sense

tacit magnet
#

Yeah, all points that satisfy that eq

dire glen
#

ok cool, thanks! 🙂

keen kiln
#

what is 4x2

keen kiln
#

what is this

#

anyways

#

I need to learn pi

#

by today

#

cause

#

my teacher said im gonna get in trouble if I don

#

dont

#

so if theres any albert eisnstion

#

einstein

#

who knows the 10 digits of pi

#

first 10

neat lintel
#

albert einstein died long ago, i'm sorry to inform

keen kiln
#

well thtas a shame

#

no pi for me I guess

neat lintel
#

did he even know that many digits of pi?

neat lintel
#

by hand

#

is this for a numerical analysis class?

dire glen
#

if det(A) = 0 Ax=b usually has no solutions, but has solutions for some b

i understand if determinant is zero, i can have zero solutions or infinite solutions. what does it means "solutions for some b" ?

keen kiln
river moon
neat lintel
dire glen
#

but they assume b is not zero here

neat lintel
#

there might be other b's for which Ax=b is solvable

dire glen
#

would that be the infinite solution case?

keen kiln
#

Whats that mean

river moon
#

homogeneous system with singular matrix have infinite number of solutions, yes

keen kiln
#

say what

neat lintel
#

over an infinite field yeah

keen kiln
#

why are u guys talking like scientist

neat lintel
#

i never saw a scientist talking like this

lone rover
#

pi number?

#

just gg it and the gg will tell you

deft willow
#

can anyone help me factorise this
5x2+ 12x – 9

keen kiln
neat lintel
keen kiln
#

what about mathmatictitiaitaian

deft willow
rocky shuttle
#

mathematactician

deft willow
lone rover
#

lollllllllll

#

just solve to have the solution

#

and take the solution back to fractorise

deft willow
lone rover
#

so what is that answer?

river moon
#

answers provided by manual search are often far more reliable than what chatgpt says

lone rover
#

at I can see in the google that is just : 5x^2 +12x-9 = 5x^2 +15x - 3x - 9

#

and you can fractorise it fo (5x - 3)(x+3)

limpid bridge
#

*rounded, because if i do so, the 2 last digit is my birthday

keen kiln
#

i dont know bro

vernal token
#

Are you being asked to write down the first 10 digits of pi in your math class or what

keen kiln
#

i dont know

#

just have to learn it

vernal token
#

Of course you should know pi is about 3.14

#

Maybe your teacher meant that?

keen kiln
#

maybe she did maybe she didn't

#

I have no diea tho

#

theres a song about it right?

vernal token
keen kiln
#

song about pi

vernal token
keen kiln
#

oh

#

alright

#

got it

vernal token
# keen kiln alright

Like you can find series expansions of it, like Ramanujan did, then you can compute billions of digits with a computer fairly quickly

keen kiln
#

whos ramanujan

vernal token
#

An indian mathematician, he was largely self-taught, barely had resources but discovered very influential things

#

He was also extremely poor and couldn't even afford paper

keen kiln
#

where is he now?

vernal token
#

He lived from 1887 - 1920

keen kiln
#

ohhhhhhhhh

#

got it

vernal token
#

For pi

#

With every single summand, 6 or 7 digits of pi are added

#

Also, it's not really known how he discovered it

keen kiln
#

do we got any photos or videos of him?

keen kiln
#

is this link safe

vernal token
keen kiln
#

ok ill click it

vernal token
#

I googled "Ramanujan", went to "images", and linked it

keen kiln
#

ok its safe

vernal token
# keen kiln ok its safe

Why'd someone who has been in this server for this long, using it daily, post an unsafe link and get banned opencry

fresh gull
#

Hello!

cyan parrot
#

I don't know if that was supposed to be modest or actually true.

neat lintel
#

so that's where the people malding over cleo on mse got it from

glass peak
#

Holy shit Cleo is the reincarnation of Ramanujan uponthewitnessing

dire glen
latent edge
#

Cleo, the integral God

cyan parrot
fresh comet
#

i wonder how cleo is doing nowadays

latent edge
#

same

sly flint
#

but again, those are just speculations

latent edge
#

why talented people are cursed

sly flint
#

Ikr cat_happycry

stoic relic
#

No its not

#

snot

little quest
vernal token
neat lintel
#

Guys pls

#

Help me

#

Does anyone here know how too make like a ying yang or like an apple polar graph on desmos

#

Oh this isn't main woops

rocky shuttle
#

H&M

burnt ledge
proud oriole
burnt ledge
#

im not scamming

#

thats just what H&M is

#

they sell clothes

burnt radish
#

yoo

#

is there an actual formula for finding square roots

#

idk

#

haven't found one

#

I hope i don't get kicked for talking to myself

#

bro

#

you won't

#

so an formula for finding square roots,

#

why not try google

#

i tried

wild lantern
#

I've only ever done it by hand using newton's method or series stuff.

#

In the US apparently people used to be taught methods for calculating square roots by hand.

burnt radish
#

but now they don't?

#

damn calculators

wild lantern
#

Yeah afaik it is uncommon

burnt radish
#

wait

#

your about me

#

is it just random

#

or did you

#

i ain't gonna touch grass

wild lantern
#

Lmao

#

Apparently there is a wiki page discussing a bunch of different square root calculation methods

burnt radish
#

bro thank you

wild lantern
#

No problem

thorn brook
neat lintel
#

hi

strange mesa
neat lintel
#

IS ANYONE um german and good at maths

granite hound
#

So I'm TAing a class and I'm usually pretty good at responding to questions by email

#

But there was an assignment due yesterday and tons of people wanted help on Saturday/Sunday

#

Which I was very much not going to do

#

But the assignment got extended to Tuesday, so now I need to answer all these emails I was ignoring 😭

#

(People had 3 weeks to ask me questions during work hours, so I feel justified in ignoring them on the weekend)

neat lintel
#

I need some help regarding PINN (Physics Informed Neural Network). Please DM if u can help. I need a serious help

night notch
#

I got no help in #discussion , I set my role to studying yet I still get Helper pings? All it did was revoke my access to general channels.

granite hound
#

3rd year Compsci class, programming language paradigms

vernal token
#

You have to TA that as a math major?

night notch
#

Yes someone told me its only for turning off general chat

#

I'm dumb anyways

#

there's literally a do not disturb feature on discord

granite hound
night notch
#

I'm usually on my laptop which has do not disturb connect to phone as well so I just set my phone to do not disturb and it blocks everything for me

#

but since I'm on my pc I was still getting notis lol

granite hound
vernal token
night notch
#

its okay, like I said it was a total brainfart because do not disturb mode solves this issue for me and blocks all channels. I've just never had to use it before so it didn't occur to me

surreal sapphire
#

the helper role is for helper pings, if you dont want general channels, you want the studying role

night notch
#

Was just not thinking 🙂

strange mesa
#

It's been like 6 hours.

ocean harbor
#

I know

#

I check this often now

strange mesa
#

Well thank you for checking up on me.

ocean harbor
#

np

strange mesa
#

I appreciate it.

ocean harbor
ocean harbor
scenic thunder
#

Hi, guys, how do people know that certain university has a strong faculty in certain directions

river moon
#

asking people involved in it's work or it's students

scenic thunder
#

Thanks!

neat lintel
#

I need some help regarding (PINN-Physics Informed Neural Network) to make an AI that solves a non linear differential equation. Someone with enough knowledge about this please DM.

neat lintel
mental stratus
#

hmm

ocean harbor
#

why do you even turn the ping off smh

#

but I guess be more patient?

cloud vector
#

dead aah

ocean harbor
worldly root
#

cat :)

brazen mulch
#

literally cat

ocean harbor
brazen mulch
#

please describe foto

bright hill
burnt ledge
# brazen mulch please describe foto

A person writes a numbered list in very small Japanese script on centimetre grid paper with a pink ballpoint pen with black ink. A very small kitten is sitting on the hand, maybe looking at the writing. In the background there is a messy arrangement of stationery

brazen mulch
bright hill
#

cat teaches hooman how to write japanese (it's getting frustrated with how slow hooman is)

burnt ledge
#

If I had to guess, that's centimetre grid paper

#

Looks slightly bigger than my regular 8mm ruled paper, in relation to the pen

brazen mulch
#

is 8 mm or 10 mm grid better to you

burnt ledge
#

ive never seen 8mm grid

brazen mulch
#

I have

mostly in primary school notebooks

burnt ledge
#

thats 5mm grid

brazen mulch
#

nah, it’s 8

burnt ledge
#

8mm is ruled

brazen mulch
#

(I measured fr)

burnt ledge
#

when theres only horizontal lines its 8mm, when theres a grid itd 5mm

brazen mulch
#

I don’t buy 8 mm grid anymore, but I swear they existed

#

and 5 mm is the one that never appeared here

burnt ledge
#

here = ?

brazen mulch
#

where I live

burnt ledge
#

U said orimary school so i assume UK

#

But i also mean UK

brazen mulch
#

💀
we operated under a bad assumption of the other’s place of residence

#

“primary school” isn’t exclusive tho
at least when it’s translated

burnt ledge
#

Ah okay

#

id still be surprised about 8mm grid ngl

hazy ice
#

Yw all

naive galleon
#

Anyone wanna hear my cool proof i have to present infron my entire class tmr?

naive galleon
#

Differential equations

vapid furnace
#

I don’t know enough about it, sorry

ocean harbor
#

@tame egret you are alive 😮

#

where have you been?

magic meteor
#

why don't more people study math on their own terms, by themselves

midnight briar
#

its not meaningful for most

#

like how can you make money?

magic meteor
#

most people, even if their interested, wait until they can get a degree out of it

#

why this clinginess to life

fresh comet
#

wait wtf

#

why did i get Helpful role

#

i havent helped people consistently in weeks

#

wtf

visual breach
fresh comet
#

yes

#

that was like 2 months ago

visual breach
#

Yeah, that's likely why

fresh comet
#

my consistency in help channels hasnt been there for weeks now

visual breach
#

Hmmm

fresh comet
#

who assigns the Helpful role

#

bot?

#

or is it like the mods or something

fresh comet
#

@neat lintel update on uoft's restrictions on UG math students: apparently no 3rd year UGs or below can take grad courses starting next semester

#

really annoying actually

jovial ember
#

Not surprised

vale plover
#

too many people taking them?

#

i can understand if ugs are crowding out grad students

midnight briar
#

i just turned in my homweork and realized every questions had divergence as an answer now im paranoid

bronze pelican
#

Literally what is the reasoning

fresh comet
#

I don’t know the reasoning

#

I heard it from a senior

#

if I had to guess, it’s probably for some stupid reason as usual lmao

fresh comet
#

Either way, it’s a very stupid policy imo

solid snow
#

Theyre losing out on money too lel

neat lintel
#

shit like this is why i accepted my other offer

vernal token
fresh comet
neat lintel
#

yeah

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toronto just keeps getting worse and worse

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but the worst mistake they could ever make was failing to immediately accept me

fresh comet
mental stratus
full tusk
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hello guiz do you know how to laplace tranform?

neat lintel
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no

neat lintel
full tusk
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that's not a place hahaha

sharp cave
mint patio
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@fresh comet

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so basically

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given a physical system (described by a linear ODE) with an input and an output, we take the Laplace transform of the system and take the ratio of the output to the input

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so if the output is y(t) and the input is r(t), the ratio is Y(s)/R(s)

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we call this the transfer function

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now uh basically the idea is

vernal token
mint patio
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we design a "controller" (a brain) that changes the input based on some parameters we select right

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one important part of the controller is what's called the gain

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dw about what it means technically, just know that higher gain means a faster controller (your brain responds faster) but it also leads to greater instability (your brain might overshoot the proper answer or start going into a spiral)

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and so the gain is something the engineer chooses based on some design criteria

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now, given a system whose transfer functionis defined as G(s)