Morera's theorem
E825426
Morera's theorem is a fundamental result in complex analysis that characterizes holomorphic functions by stating that a continuous function with zero integral over every closed contour in a domain must be analytic there.
Statements (44)
| Predicate | Object |
|---|---|
| instanceOf | theorem in complex analysis ⓘ |
| appearsIn |
graduate complex analysis courses
ⓘ
undergraduate complex analysis courses ⓘ |
| appliesTo | continuous complex-valued functions ⓘ |
| assumption |
function is continuous on the domain
ⓘ
integral over every triangle in the domain is zero (common variant) ⓘ |
| characterizes | holomorphic functions ⓘ |
| conclusion |
the function is analytic on the domain
ⓘ
the function is holomorphic on the domain ⓘ |
| condition | the integral of the function over every closed contour in the domain is zero ⓘ |
| doesNotRequire | prior existence of complex derivative ⓘ |
| domainOfApplication | open subsets of the complex plane ⓘ |
| equivalentFormulation | if the integral of a continuous function over every closed triangle in a domain is zero, then the function is holomorphic ⓘ |
| field | complex analysis ⓘ |
| generalizationOf | characterizations of holomorphic functions via vanishing integrals on special families of curves ⓘ |
| givesCriterionFor |
analyticity
ⓘ
holomorphy ⓘ |
| hasGeneralization |
Morera-type theorems in several complex variables
ⓘ
Morera-type theorems on Riemann surfaces NERFINISHED ⓘ |
| historicalPeriod | late 19th century ⓘ |
| holdsIn |
general domains in the complex plane
ⓘ
simply connected domains ⓘ |
| implies |
existence of complex derivative at every point of the domain
ⓘ
function satisfies Cauchy–Riemann equations (in the interior) ⓘ |
| language | mathematical logic and analysis ⓘ |
| logicalRole | converse to Cauchy integral theorem (up to continuity assumption) ⓘ |
| mathematicalSubjectClassification | 30-XX (functions of a complex variable) ⓘ |
| namedAfter | Giuseppe Morera NERFINISHED ⓘ |
| proofTechnique | approximation of curves by polygonal paths or triangles ⓘ |
| relatedTo |
Cauchy integral formula
NERFINISHED
ⓘ
Cauchy integral theorem NERFINISHED ⓘ Goursat's theorem NERFINISHED ⓘ |
| requires |
Green's theorem in typical proofs
ⓘ
continuity of the function on the domain ⓘ |
| standardReference | textbooks on complex analysis ⓘ |
| statementStyle | if-and-only-if characterization of holomorphicity via contour integrals ⓘ |
| typeOfCriterion | integral criterion ⓘ |
| usedFor |
proving that a function is holomorphic without computing derivatives
ⓘ
showing locally uniform limits of holomorphic functions are holomorphic ⓘ showing uniform limits of holomorphic functions are holomorphic ⓘ |
| usedInProofOf | Weierstrass theorem on uniform limits of holomorphic functions NERFINISHED ⓘ |
| usesConcept |
Cauchy integral theorem
NERFINISHED
ⓘ
closed contour ⓘ contour integral ⓘ |
Referenced by (3)
Full triples — surface form annotated when it differs from this entity's canonical label.