From 777f9d3fd8caf56e6bc6999a4b05379307d0733f Mon Sep 17 00:00:00 2001 From: Justin Gassner Date: Tue, 12 Sep 2023 07:36:33 +0200 Subject: Initial commit --- .../one-complex-variable/cauchys-theorem.md | 39 ++++++++++++++++++++++ 1 file changed, 39 insertions(+) create mode 100644 pages/complex-analysis/one-complex-variable/cauchys-theorem.md (limited to 'pages/complex-analysis/one-complex-variable/cauchys-theorem.md') diff --git a/pages/complex-analysis/one-complex-variable/cauchys-theorem.md b/pages/complex-analysis/one-complex-variable/cauchys-theorem.md new file mode 100644 index 0000000..15412bc --- /dev/null +++ b/pages/complex-analysis/one-complex-variable/cauchys-theorem.md @@ -0,0 +1,39 @@ +--- +title: Cauchy's Theorem +parent: One Complex Variable +grand_parent: Complex Analysis +nav_order: 2 +# cspell:words +--- + +# {{ page.title }} + +{: .theorem-title } +> {{ page.title }} (Homotopy Version) +> +> Let $G$ be a connected open subset of the complex plane. +> Let $f : G \to \CC$ be a holomorphic function. +> If $\gamma_0$, $\gamma_1$ are homotopic closed curves in $G$, then +> +> $$ +> \int_{\gamma_0} \! f(z) \, dz = +> \int_{\gamma_1} \! f(z) \, dz +> $$ +> +> If $\gamma$ is a null-homotopic closed curve in $G$, then +> +> $$ +> \int_{\gamma} f(z) \, dz = 0 +> $$ + +{% proof %} +{% endproof %} + +{{ page.title }} has a converse: + +{: .theorem-title } +> Morera's Theorem +> +> Let $G \subset \CC$ be open and let $f : G \to \CC$ be a continuous function. +> If $\int_{\gamma} f(z) \, dz = 0$ for every contour $\gamma$ contained in $G$, +> then $f$ is holomorphic in $G$. -- cgit v1.2.3-54-g00ecf