Cauchy's integral theorem

For a function holomorphic on and inside a simple closed contour, the contour integral of the function around that contour is zero. It is a foundational result in complex analysis.

\oint_{C} f(z)\,\mathrm{d}z = 0

What the symbols mean

a holomorphic (complex-differentiable) function
a simple closed contour in the complex plane
complex variable of integration

About this formula

  • FieldMathematics
  • TopicComplex analysis
  • LevelUniversity
  • Also calledCauchy's theorem, contour integral zero, holomorphic function contour integral, complex analysis closed contour integral
  • SourceWikidata Q834025

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