Every idea

Ideas 12151–12300 of 14167.

Name	Kind	Subject
Expansive homeomorphism	Concept	Dynamical systems and ergodic theory
Abian–Brown theorem	Theorem	Order, lattices, ordered algebraic structures
Bicategory	Concept	Category theory; homological algebra
Fractional integration	Definition	Harmonic analysis on Euclidean spaces
Tautological one-form	Definition	Differential geometry
Kawamata–Viehweg vanishing theorem	Theorem	Algebraic geometry
Integral geometry	Concept	Convex and discrete geometry
Ring of differential operators	Definition	Associative rings and algebras
Langevin equation	Definition	Probability theory and stochastic processes
Lévy–Prokhorov metric	Definition	Probability theory and stochastic processes
Direct limit	Definition	Category theory; homological algebra
Algebraic statistics	Concept	Statistics
Möbius–Kantor configuration	Example	Combinatorics
Square wave	Example	Harmonic analysis on Euclidean spaces
Gerstenhaber algebra	Definition	Nonassociative rings and algebras
Faithful module	Concept	Associative rings and algebras
Picard–Vessiot extension	Concept	Field theory and polynomials
Sheaf	Concept	General topology
Saddle-node bifurcation	Definition	Ordinary differential equations
Space form	Definition	Differential geometry
Discriminant of a field extension	Definition	Number theory
Hamburger moment problem	Problem	Integral transforms, operational calculus
Triebel–Lizorkin space	Concept	Functional analysis
Krull's height theorem	Theorem	Commutative algebra
Levi-flat hypersurface	Definition	Several complex variables and analytic spaces
Crown	Example	Order, lattices, ordered algebraic structures
Cauchy's logarithmic equation	Definition	Difference and functional equations
Universal Turing machine	Object	Mathematical logic and foundations
Discrete Laplace operator	Definition	Difference and functional equations
Foster's theorem on primal algebras	Theorem	General algebraic systems
Upper nilradical	Definition	Associative rings and algebras
Systolic geometry	Definition	Differential geometry
Cotangent space of a local ring	Definition	Commutative algebra
F-coalgebra	Definition	Category theory; homological algebra
Poisson kernel	Concept	Potential theory
Projection method for integral equations	Definition	Integral equations
Mikusiński operational calculus	Concept	Integral transforms, operational calculus
Ehresmann connection	Concept	Differential geometry
Coupling	Definition	Probability theory and stochastic processes
Magnus expansion	Definition	Ordinary differential equations
Backward differentiation formula	Concept	Numerical analysis
Multiple integral	Definition	Real functions
Tietze transformations	Definition	Group theory and generalizations
Peixoto's theorem	Theorem	Dynamical systems and ergodic theory
Direct and inverse theorems of approximation	Concept	Approximations and expansions
Abel inversion formula	Theorem	Integral equations
Extremal length	Definition	Functions of a complex variable
Kaplansky density theorem	Theorem	Functional analysis
Invertible ideal	Definition	Commutative algebra
Kodaira–Spencer map	Definition	Several complex variables and analytic spaces
Bessel function of the first kind	Definition	Special functions
Functional completeness	Concept	General algebraic systems
Tarski monster group	Object	Group theory and generalizations
Direct method in the calculus of variations	Concept	Calculus of variations and optimal control; optimization
Periodic point	Definition	Dynamical systems and ergodic theory
Hirzebruch signature theorem	Theorem	Manifolds and cell complexes
Hopf invariant	Concept	Algebraic topology
Lagrange polynomial	Definition	Approximations and expansions
Resolvent	Definition	Operator theory
Finite ring	Definition	Associative rings and algebras
Aleph number	Definition	Mathematical logic and foundations
Descriptive set theory	Concept	Mathematical logic and foundations
Exact category	Concept	Category theory; homological algebra
Uniform approximation	Definition	Approximations and expansions
Pivotal quantity	Definition	Statistics
Lie sphere geometry	Concept	Geometry
Capacity of a set	Definition	Potential theory
Banach algebra	Definition	Functional analysis
Geometric realization	Concept	Algebraic topology
ℓ-adic cohomology	Definition	Algebraic geometry
Chevalley's theorem on constructible sets	Theorem	Algebraic geometry
Join-prime element	Definition	Order, lattices, ordered algebraic structures
Down-closure	Definition	Order, lattices, ordered algebraic structures
Newton's minimal resistance problem	Problem	Calculus of variations and optimal control; optimization
Block design	Definition	Combinatorics
Residually small variety	Concept	General algebraic systems
Integro-partial differential equation	Concept	Integral equations
Levenberg–Marquardt algorithm	Proposition	Numerical analysis
Proof theory	Definition	Mathematical logic and foundations
Resistance form	Concept	Potential theory
Hartogs domain	Concept	Several complex variables and analytic spaces
Generalized linear model	Definition	Statistics
Free category	Concept	Category theory; homological algebra
Differential game	Concept	Game theory, economics, finance, and other social and behavioral sciences
Siu's semicontinuity theorem	Theorem	Several complex variables and analytic spaces
Spectral triple	Definition	Global analysis, analysis on manifolds
Paley–Wiener theorem	Theorem	Functions of a complex variable
Random graph	Definition	Combinatorics
Group scheme	Concept	Algebraic geometry
Normal form	Concept	Ordinary differential equations
The alternating group is the kernel of the sign	Example	Group theory and generalizations
Discrete Fourier transform	Definition	Numerical analysis
Finitely presented group	Concept	Group theory and generalizations
Ore condition	Concept	Associative rings and algebras
Catastrophic cancellation	Concept	Numerical analysis
Hahn series	Definition	Commutative algebra
Differential game	Definition	Game theory, economics, finance, and other social and behavioral sciences
Lichnerowicz–Obata eigenvalue theorem	Theorem	Global analysis, analysis on manifolds
Hyperreal number	Definition	Real functions
Analytic continuation in several variables	Definition	Several complex variables and analytic spaces
Holomorphic vector bundle	Concept	Several complex variables and analytic spaces
Integral transforms of tempered distributions	Definition	Functional analysis
Filtered category	Definition	Category theory; homological algebra
Cluster algebra	Concept	Commutative algebra
Nonharmonic Fourier series	Concept	Harmonic analysis on Euclidean spaces
Elastic net	Concept	Statistics
Taft algebra	Example	Associative rings and algebras
Function of exponential order	Concept	Integral transforms, operational calculus
Domain decomposition methods	Definition	Numerical analysis
Schur product theorem	Theorem	Linear and multilinear algebra; matrix theory
Proper holomorphic map	Concept	Several complex variables and analytic spaces
Löwner–John theorem	Theorem	Convex and discrete geometry
Free product	Concept	Group theory and generalizations
Borel density theorem	Theorem	Topological groups, Lie groups
Boundary value problem	Concept	Ordinary differential equations
Nevanlinna class	Definition	Functions of a complex variable
Scott continuity	Definition	Order, lattices, ordered algebraic structures
Eichler order	Definition	Number theory
Separation principle	Theorem	Systems theory; control
Degree of a continuous map	Concept	Algebraic topology
Semilocally simply connected space	Definition	Manifolds and cell complexes
Semiprimitive ring	Definition	Associative rings and algebras
Bifurcation in a family of maps	Definition	Difference and functional equations
Gegenbauer transform	Concept	Integral transforms, operational calculus
Primary ideal	Concept	Commutative algebra
Iterated function system	Definition	Measure and integration
Neighborly polytope	Definition	Convex and discrete geometry
Nome	Definition	Special functions
Friendship theorem	Theorem	Combinatorics
Laplacian matrix	Concept	Combinatorics
Computably enumerable set	Concept	Mathematical logic and foundations
Formal group law in topology	Concept	Algebraic topology
Roe solver	Proposition	Numerical analysis
Hadamard three-circle theorem for subharmonic functions	Theorem	Potential theory
Baby Monster group	Object	Group theory and generalizations
Random graph	Concept	Combinatorics
Fundamental theorem of space curves	Theorem	Differential geometry
Stable vector bundle	Definition	Algebraic geometry
Approximately additive function	Definition	Difference and functional equations
Bürmann–Lagrange series	Theorem	Functions of a complex variable
Rank-one convexity	Definition	Calculus of variations and optimal control; optimization
Complex powers of elliptic operators	Definition	Global analysis, analysis on manifolds
Whitehead link	Example	Manifolds and cell complexes
Proper map	Definition	General topology
Fejér's theorem	Theorem	Harmonic analysis on Euclidean spaces
Romberg's method	Definition	Numerical analysis
Barycentric interpolation formula	Proposition	Numerical analysis
Hörmander's L2 estimates	Theorem	Several complex variables and analytic spaces
Axiom of dependent choice	Definition	Mathematical logic and foundations
Federer–Fleming compactness theorem	Theorem	Calculus of variations and optimal control; optimization