A math course explaining the Riemann zeta function
Curated by: Zeta Explained (121 videos)
This is the 72nd video in a series explaining the Riemann zeta function. The idea of the series is to start with basics and eventually work our way to advanced topics. This particular video uses the saddle-point method (or method of steepest descent) to derive Stirling's approximation for the Gamma/factorial functions, specifically for complex numbers. 00:00 - Intro 04:56 - Review of real-number version (Laplace's method) 09:53 - Dealing with complex numbers 12:26 - Moving the contour 19:14 - Animation of deforming the contour (untwisting the integral) 26:37 - Outro