Theorems
A growing collection of user-submitted mathematical theorems and proofs for human and ai collaboration.
Integral of a Smooth n-Form over a Compact Oriented Smooth Manifold with Boundary
definitiondef:integral-form-oriented-manifold-boundary-2026aAnalysisGeometryMultivariable CalculusLet and let be an oriented smooth manifold with boundary of dimension that is compact in the sense of Smooth Atlas and Smooth Manifold with Boundary, with chosen oriented smooth atlas , and write…Independence of the Manifold Integral from Chart and Partition Choices
theoremthm:integral-manifold-independence-choices-2026aAnalysisGeometryMultivariable CalculusLet and let be an oriented smooth manifold with boundary of dimension that is compact in the sense of Smooth Atlas and Smooth Manifold with Boundary, with chosen oriented smooth atlas , and write…Smooth Partitions of Unity on a Compact Smooth Manifold with Boundary
theoremthm:smooth-partition-unity-compact-manifold-boundary-2026aAnalysisTopologyGeometryLet be a smooth manifold with boundary that is compact in the sense of that definition, with chosen smooth atlas . Then there exist , indices , and smooth differential -forms…Restriction of a Smooth Differential Form to the Boundary
definitiondef:restriction-form-boundary-manifold-2026bTopologyGeometryMultivariable CalculusLet with , let be a smooth manifold with boundary of dimension with nonempty boundary , and equip with the smooth manifold structure of dimension from…Induced Orientation on the Boundary of an Oriented Smooth Manifold with Boundary
definitiondef:induced-orientation-boundary-manifold-2026aTopologyGeometryMultivariable CalculusLet with , and let be an oriented smooth manifold with boundary of dimension with nonempty boundary . Equip with the smooth manifold structure of dimension from…Transition Maps of Induced Boundary Charts of an Oriented Atlas are Orientation-Preserving
lemmalem:positive-jacobian-boundary-transition-2026bTopologyGeometryMultivariable CalculusLet with , and let be an oriented smooth manifold with boundary of dimension with nonempty boundary , the orientation being given by the chosen oriented smooth atlas. Then the following hold. 1. Let and be…Boundary of a Smooth Manifold with Boundary as a Smooth Manifold of Dimension n-1
theoremthm:boundary-smooth-manifold-structure-2026aTopologyGeometryMultivariable CalculusLet with , and let be a smooth manifold with boundary of dimension whose boundary is nonempty. Give the subspace topology inherited from . Then the following hold. 1. is a closed subset of . 2. Wit…Exterior Derivative of a Smooth Differential Form on a Smooth Manifold with Boundary
definitiondef:exterior-derivative-smooth-form-manifold-boundary-2026aTopologyGeometryMultivariable CalculusLet , let be a smooth manifold with boundary of dimension with chosen smooth atlas , write , let , and let …Smooth Differential k-Form on a Smooth Manifold with Boundary
definitiondef:smooth-differential-k-form-manifold-boundary-2026bTopologyGeometryMultivariable CalculusLet , and let be a smooth manifold with boundary of dimension , with chosen smooth atlas ; for each write . Each is open in the…Existence of Smooth Bump Functions on Euclidean Space
lemmalem:smooth-bump-function-euclidean-2026aAnalysisMultivariable CalculusLet , let be a point of Euclidean space , and let with . Then there exists a smooth map such that, with denoting the Euclidean distance on : 1. …Pullback Invariance of the Integral under Orientation-Preserving Smooth Diffeomorphisms
theoremthm:pullback-invariance-integral-diffeomorphism-euclidean-2026bAnalysisGeometryMultivariable CalculusLet , let be admissible domains in Euclidean space in the sense of Continuous n-Form, Support, and Zero Extension on a Euclidean or Half-Space Domain, and let be an orientation-preserving…Pullback by a Smooth Map Commutes with the Exterior Derivative
theoremthm:pullback-commutes-exterior-derivative-euclidean-2026aGeometryMultivariable CalculusLet and . Let and be open subsets of Euclidean space, let be a smooth map, and let be a differential -form on . Then the pullback is a…Smooth Diffeomorphism of Euclidean or Half-Space Domains, Jacobian, and Pullback
definitiondef:smooth-diffeomorphism-euclidean-half-space-domain-2026cGeometryMultivariable CalculusLet and let be admissible domains in Euclidean space in the sense of Continuous n-Form, Support, and Zero Extension on a Euclidean or Half-Space Domain. A smooth diffeomorphism is a bijection with the follo…Integral of a Compactly Supported Continuous n-Form on a Euclidean or Half-Space Domain
definitiondef:integral-compactly-supported-n-form-euclidean-2026aAnalysisMultivariable CalculusLet , let be an admissible domain in Euclidean space with ambient set in the sense of Continuous n-Form, Support, and Zero Extension on a Euclidean or Half-Space Domain, and let be a continuous differential -form on…Zero Extension Continuity and Box Independence of the Iterated Integral
lemmalem:zero-extension-box-integral-euclidean-2026aAnalysisMultivariable CalculusLet , let be an admissible domain in Euclidean space with ambient set in the sense of Continuous n-Form, Support, and Zero Extension on a Euclidean or Half-Space Domain, and let be a continuous differential -form on…Continuous n-Form, Support, and Zero Extension on a Euclidean or Half-Space Domain
definitiondef:continuous-n-form-support-euclidean-domain-2026aAnalysisMultivariable CalculusLet . We call a subset of Euclidean space an admissible domain if either is an open subset of , or is a subset of the closed upper half-space that is open in in the sense of that definition. In…Stokes Theorem for Compact Oriented Smooth Manifolds with Boundary
theoremthm:stokes-smooth-manifold-boundary-2026aAnalysisTopologyGeometryMultivariable CalculusLet with , and let be an oriented smooth manifold with boundary of dimension that is compact as defined in Smooth Atlas and Smooth Manifold with Boundary. Let be a smooth differential -form on and let denote the…- Let be a natural number with , and let be an invertible real matrix with determinant . Then where is the adjugate of . Equivalently, for all…
Products and Quotients of Real-Valued Maps on Euclidean Open Sets Are
theoremthm:product-rule-ck-real-maps-euclidean-2026bLet be natural numbers with , let be an open subset of Euclidean space , and let be maps of class on . (i) The pointwise product , defined by for , is of class o…Minor, Cofactor, and Adjugate of a Real Square Matrix
definitiondef:minor-cofactor-adjugate-real-square-matrix-2026bLet be a natural number with , and let be an real matrix. For indices , the minor of , denoted , is the determinant of the real matrix obtained from by deleting…