worn vector
I am trying to understand Jordan's Lemma, and 1 thing(among others) that I don't understand is, why are the poles below the real axis omitted?
Is it for the sake of the lemma/teaching? E.g the process is repeated the same way for the point below the real axis?
When applying it, should I repeat it for a semicircle below the real line?
Or is finding the total sum of residues above the real axis the "whole picture" as far as the indefinite integral along the real axis goes? And I should not repeat for the poles below the real line.
sharp lotus