Every idea

Ideas 9901–10050 of 10181.

Name	Kind	Subject
d'Alembert's formula	Theorem	Partial differential equations
Topology of uniform convergence	Concept	General topology
Jacobi field	Definition	Differential geometry
Deformation retract	Definition	General topology
Club set	Concept	Mathematical logic and foundations
Toric variety	Concept	Algebraic geometry
Instanton	Concept	Differential geometry
Isomorphism	Definition	General algebraic systems
Weierstrass–Enneper parameterization	Theorem	Differential geometry
Uniform space	Definition	General topology
Trace form	Concept	Field theory and polynomials
Smn theorem	Theorem	Mathematical logic and foundations
Rate of convergence	Concept	Sequences, series, summability
Koszul duality	Definition	Associative rings and algebras
Loewner differential equation	Definition	Functions of a complex variable
Exceptional Lie group G2	Example	Topological groups, Lie groups
Hadwiger–Nelson problem	Problem	Combinatorics
Uniform module	Concept	Associative rings and algebras
Group cohomology	Concept	Group theory and generalizations
Projective object	Concept	Category theory; homological algebra
Arakelov theory	Concept	Algebraic geometry
Classification of covering spaces	Theorem	Manifolds and cell complexes
Fractional differential equation	Concept	Ordinary differential equations
Gelfand–Kirillov dimension	Definition	Associative rings and algebras
Kirby–Siebenmann class	Definition	Manifolds and cell complexes
J-homomorphism	Concept	Algebraic topology
Measurable function	Concept	Measure and integration
Connes embedding problem	Problem	Functional analysis
Manifold with boundary	Definition	Manifolds and cell complexes
Lying over theorem	Theorem	Commutative algebra
Measure algebra	Concept	Measure and integration
Symmetric algebra	Definition	Linear and multilinear algebra; matrix theory
Calabi–Yau manifold	Definition	Algebraic geometry
Field of formal Laurent series	Concept	Commutative algebra
Arity	Definition	General algebraic systems
Slice category	Definition	Category theory; homological algebra
Koszul complex	Concept	Commutative algebra
Schubert variety	Concept	Algebraic geometry
Semicontinuity	Definition	General topology
Chern–Simons form	Definition	Differential geometry
Uniserial module	Concept	Associative rings and algebras
Order filter	Concept	Order, lattices, ordered algebraic structures
Duality in category theory	Definition	Category theory; homological algebra
Cotangent space of a local ring	Concept	Commutative algebra
Difference algebra	Concept	Field theory and polynomials
Abel summation	Definition	Sequences, series, summability
Subharmonic function	Concept	Potential theory
Frobenius group	Definition	Group theory and generalizations
Maximal torus	Definition	Topological groups, Lie groups
Trace class operator	Concept	Operator theory
Horner's method	Definition	Computer science
Parabolic subgroup	Concept	Topological groups, Lie groups
Lumer–Phillips theorem	Theorem	Operator theory
Morrey's inequality	Theorem	Functional analysis
Trace operator	Concept	Functional analysis
Hadamard product	Definition	Linear and multilinear algebra; matrix theory
Osculating circle	Definition	Differential geometry
Positive cone	Concept	Functional analysis
Littlewood's Tauberian theorem	Theorem	Sequences, series, summability
Lattice in a Lie group	Definition	Topological groups, Lie groups
Spectrum	Definition	Algebraic topology
Plane curve	Definition	Algebraic geometry
Weierstrass equation	Concept	Algebraic geometry
Algebraic logic	Concept	Mathematical logic and foundations
Henselian field	Definition	Field theory and polynomials
Pushout	Definition	Category theory; homological algebra
Myers–Steenrod theorem	Theorem	Differential geometry
Exact category in the sense of Barr	Definition	Category theory; homological algebra
Hairy ball theorem	Theorem	Manifolds and cell complexes
Lattice (group)	Definition	Number theory
Summation of families over arbitrary index sets	Definition	Sequences, series, summability
Condensed set	Definition	Category theory; homological algebra
Character of a representation	Definition	Group theory and generalizations
O'Nan–Scott theorem	Theorem	Group theory and generalizations
Abstract Wiener space	Definition	Measure and integration
Primitive ideal	Definition	Associative rings and algebras
Doob martingale	Example	Probability theory and stochastic processes
Band matrix	Concept	Linear and multilinear algebra; matrix theory
Oracle machine	Concept	Mathematical logic and foundations
Relatively complemented lattice	Definition	Order, lattices, ordered algebraic structures
Duality in category theory	Concept	Category theory; homological algebra
Projective morphism	Concept	Algebraic geometry
3-manifold	Definition	Manifolds and cell complexes
No-retraction theorem	Theorem	Algebraic topology
Current	Definition	Calculus of variations and optimal control; optimization
Four-vertex theorem	Theorem	Differential geometry
Normal Moore space problem	Problem	General topology
Locally compact abelian group	Definition	Topological groups, Lie groups
Inherently nonfinitely based algebra	Concept	General algebraic systems
Triebel–Lizorkin space	Definition	Functional analysis
Massey product	Concept	Algebraic topology
Girsanov theorem	Theorem	Probability theory and stochastic processes
Monomial ideal	Definition	Commutative algebra
Interior operator	Concept	Order, lattices, ordered algebraic structures
Solvable by radicals	Definition	Field theory and polynomials
Golden–Thompson inequality	Theorem	Linear and multilinear algebra; matrix theory
Sard's theorem	Theorem	Global analysis, analysis on manifolds
Successor order	Definition	Order, lattices, ordered algebraic structures
Undecidability of the halting problem	Theorem	Mathematical logic and foundations
Curve-shortening flow	Definition	Differential geometry
Tensor decomposition	Definition	Linear and multilinear algebra; matrix theory
Word problem for free lattices	Theorem	Order, lattices, ordered algebraic structures
Stone–von Neumann theorem	Theorem	Topological groups, Lie groups
Essentially self-adjoint operator	Definition	Operator theory
Finite-rank operator	Concept	Operator theory
Synge's theorem	Theorem	Differential geometry
Monogenic function	Definition	Functions of a complex variable
Martin's axiom	Definition	Mathematical logic and foundations
Christoffel symbols	Definition	Differential geometry
Congruence lattice	Definition	General algebraic systems
Reeb stability theorem	Theorem	Manifolds and cell complexes
Kervaire invariant problem	Problem	Algebraic topology
Weil divisor	Concept	Algebraic geometry
Topological manifold	Definition	Manifolds and cell complexes
Flag variety	Definition	Algebraic geometry
Prime ring	Concept	Associative rings and algebras
Symbol class	Definition	Partial differential equations
Hurewicz theorem	Theorem	Algebraic topology
Dehn surgery	Concept	Manifolds and cell complexes
CSP dichotomy theorem	Theorem	General algebraic systems
Singular perturbation	Definition	Ordinary differential equations
Curvature form	Concept	Differential geometry
Well-founded order	Definition	Order, lattices, ordered algebraic structures
Allen–Cahn equation	Definition	Partial differential equations
Moment map	Concept	Differential geometry
First and second variation of arc length	Theorem	Differential geometry
Gowers norm	Concept	Number theory
Theta correspondence	Concept	Number theory
Fundamental groupoid	Concept	Algebraic topology
Category of posets	Concept	Category theory; homological algebra
Cauchy's functional equation	Problem	Difference and functional equations
Cartan matrix of an algebra	Concept	Associative rings and algebras
Bernstein's theorem on monotone functions	Theorem	Real functions
Fuchsian equation	Concept	Ordinary differential equations
Quadratic variation	Definition	Probability theory and stochastic processes
Normal form	Definition	Ordinary differential equations
Universal bundle	Definition	Algebraic topology
Beth number	Definition	Mathematical logic and foundations
Lawson topology	Concept	Order, lattices, ordered algebraic structures
Hermite equation	Example	Ordinary differential equations
Regular cardinal	Definition	Mathematical logic and foundations
Varifold	Definition	Calculus of variations and optimal control; optimization
Immersion	Definition	Manifolds and cell complexes
Concrete category of algebras	Concept	General algebraic systems
Primary decomposition	Concept	Commutative algebra
Birational map	Definition	Algebraic geometry
Barratt–Priddy–Quillen theorem	Theorem	Algebraic topology
Semilocal ring	Concept	Associative rings and algebras
Permutation group	Concept	Group theory and generalizations
Continuous lattice	Definition	Order, lattices, ordered algebraic structures