Every idea

Ideas 12001–12150 of 14167.

Name	Kind	Subject
Alexander–Spanier cohomology	Definition	Algebraic topology
Doob–Meyer decomposition theorem	Theorem	Probability theory and stochastic processes
Cartan–Eilenberg resolution	Concept	Category theory; homological algebra
Determinantal ideal	Concept	Commutative algebra
Secretary problem	Problem	Probability theory and stochastic processes
Holonomy groupoid of a foliation	Definition	Manifolds and cell complexes
Resolvent as Laplace transform of a semigroup	Theorem	Operator theory
Spherical trigonometry	Concept	Geometry
Sequential probability ratio test	Concept	Statistics
Newton polytope	Definition	Algebraic geometry
Minkowski addition	Concept	Convex and discrete geometry
Commutativity of convolution	Proposition	Integral transforms, operational calculus
Universal enveloping algebra	Definition	Nonassociative rings and algebras
Irreducible component	Concept	Algebraic geometry
Quillen adjunction	Concept	Category theory; homological algebra
Banach limit	Concept	Sequences, series, summability
Carathéodory metric	Concept	Several complex variables and analytic spaces
Decay of the Fourier transform of surface measure	Theorem	Harmonic analysis on Euclidean spaces
Euler characteristic	Definition	Algebraic topology
Matroid rank	Concept	Combinatorics
Bogomolov–Miyaoka–Yau inequality	Theorem	Algebraic geometry
Dual matroid	Definition	Combinatorics
Lusternik–Schnirelmann theorem	Theorem	Algebraic topology
Lie group method for PDEs	Definition	Partial differential equations
Kantorovich–Rubinstein duality	Theorem	Calculus of variations and optimal control; optimization
Manifold with corners	Concept	Global analysis, analysis on manifolds
Caloric function	Definition	Partial differential equations
Hadamard's example of ill-posedness	Counterexample	Partial differential equations
Gaussian quadrature	Definition	Numerical analysis
Cross-validation	Definition	Statistics
Szegő's theorem	Theorem	Harmonic analysis on Euclidean spaces
Semiorder	Definition	Order, lattices, ordered algebraic structures
Bounded poset	Definition	Order, lattices, ordered algebraic structures
Fundamental domain of the modular group	Example	Number theory
Reduced ring	Concept	Commutative algebra
Admissible representation	Concept	Topological groups, Lie groups
Ordinary point and singular point	Definition	Ordinary differential equations
Fourier–Legendre series	Definition	Harmonic analysis on Euclidean spaces
Simpson's paradox	Counterexample	Statistics
Permutohedron	Example	Convex and discrete geometry
Complemented lattice	Definition	Order, lattices, ordered algebraic structures
Morphism of finite type	Definition	Algebraic geometry
Frölicher space	Concept	Global analysis, analysis on manifolds
Moving least squares	Concept	Numerical analysis
Subalgebra lattice	Concept	General algebraic systems
Minakshisundaram–Pleijel zeta function	Concept	Global analysis, analysis on manifolds
Liouville's theorem for planar harmonic functions	Theorem	Potential theory
Band matrix	Definition	Linear and multilinear algebra; matrix theory
Positive current	Definition	Several complex variables and analytic spaces
Holomorphic map between Riemann surfaces	Concept	Functions of a complex variable
Mathieu groups	Object	Group theory and generalizations
Borel–Moore homology	Concept	Algebraic topology
Compositum of fields	Concept	Field theory and polynomials
Partial autocorrelation function	Definition	Statistics
Spectral element method	Concept	Numerical analysis
Local truncation error	Concept	Numerical analysis
Associative quotient of a magma	Concept	Group theory and generalizations
Resolvent equation for kernels	Proposition	Integral equations
Berkovich space	Concept	Algebraic geometry
Gauss's law for potentials	Theorem	Potential theory
Maximal compact subgroup	Concept	Topological groups, Lie groups
Mean curvature	Definition	Differential geometry
Fatou–Bieberbach domain	Example	Several complex variables and analytic spaces
Triangulated category	Concept	Category theory; homological algebra
Topological vector space	Concept	Functional analysis
Rate of convergence	Definition	Sequences, series, summability
Dimension of a polynomial ring	Theorem	Commutative algebra
Pseudo-spectral method	Definition	Numerical analysis
Isomorphism of topological groups	Concept	Topological groups, Lie groups
Sylvester–Gallai theorem	Theorem	Convex and discrete geometry
Reidemeister's theorem	Theorem	Manifolds and cell complexes
Optimal control	Concept	Calculus of variations and optimal control; optimization
Alexander's theorem on proper self-maps of the ball	Theorem	Several complex variables and analytic spaces
Differential field	Definition	Field theory and polynomials
Substitution tiling	Definition	Dynamical systems and ergodic theory
Primal algebra	Definition	General algebraic systems
Nijenhuis tensor	Concept	Differential geometry
Omega-complete partial order	Concept	Order, lattices, ordered algebraic structures
Topological data analysis	Definition	Statistics
4-manifold	Definition	Manifolds and cell complexes
Fourier series on the torus	Definition	Harmonic analysis on Euclidean spaces
Nerve theorem	Theorem	Algebraic topology
The alternating group A3 is normal in S3	Example	Group theory and generalizations
Sphere packing	Definition	Convex and discrete geometry
Gelfand's spectral radius formula	Theorem	Functional analysis
Recurrence relations for Bessel functions	Proposition	Special functions
Fourier inversion theorem	Theorem	Harmonic analysis on Euclidean spaces
Monotone cubic interpolation	Theorem	Numerical analysis
Doléans-Dade exponential	Definition	Probability theory and stochastic processes
Direct collocation	Concept	Calculus of variations and optimal control; optimization
Verification theorem	Theorem	Calculus of variations and optimal control; optimization
Barbier's theorem	Theorem	Convex and discrete geometry
Free distributive lattice	Concept	Order, lattices, ordered algebraic structures
Zimmer program	Definition	Dynamical systems and ergodic theory
Gårding's inequality	Theorem	Partial differential equations
Green's function of the ball	Example	Potential theory
Baum–Welch algorithm	Definition	Statistics
Baouendi–Trèves approximation theorem	Theorem	Several complex variables and analytic spaces
Modular curve	Concept	Number theory
Ambrose–Singer theorem	Theorem	Differential geometry
n-sphere	Object	Manifolds and cell complexes
Maximum principle for harmonic functions	Theorem	Potential theory
Right adjoints preserve limits	Theorem	Category theory; homological algebra
Mather's stability theorem	Theorem	Global analysis, analysis on manifolds
Discrete Poisson equation	Definition	Difference and functional equations
Descartes' rule of signs	Theorem	Real functions
Gorenstein ring	Concept	Commutative algebra
Hodges–Lehmann estimator	Concept	Statistics
Topological modular forms	Definition	Algebraic topology
Turing reduction	Definition	Mathematical logic and foundations
Steklov eigenvalue problem	Problem	Partial differential equations
Fractional calculus	Concept	Real functions
Periodic point	Concept	Dynamical systems and ergodic theory
Trigonometric integrals	Definition	Special functions
Lattice congruence	Concept	Order, lattices, ordered algebraic structures
E-infinity operad	Concept	Algebraic topology
Projective transformation	Definition	Geometry
Hammerstein integral equation	Concept	Integral equations
Ordered geometry	Concept	Geometry
Generator of a semigroup	Definition	Operator theory
Stable theory	Concept	Mathematical logic and foundations
Electrical network	Concept	Potential theory
Fenchel conjugate	Concept	Convex and discrete geometry
Inner function	Definition	Functions of a complex variable
Equivariant index theorem	Theorem	Global analysis, analysis on manifolds
Muckenhoupt weights	Concept	Harmonic analysis on Euclidean spaces
Cobordism	Concept	Manifolds and cell complexes
Multivariate division algorithm	Concept	Commutative algebra
Residuated mapping	Definition	Order, lattices, ordered algebraic structures
Neville theta functions	Definition	Special functions
q-exponential	Concept	Combinatorics
Monodromy of the hypergeometric equation	Concept	Special functions
Rational difference equation	Concept	Difference and functional equations
Bruhat decomposition	Theorem	Group theory and generalizations
Divided differences	Definition	Numerical analysis
Lebesgue's universal covering problem	Problem	Convex and discrete geometry
Wald test	Definition	Statistics
Outer function	Definition	Functions of a complex variable
Pontryagin–Thom construction	Definition	Manifolds and cell complexes
Szpilrajn extension theorem	Theorem	Order, lattices, ordered algebraic structures
Pointed space	Concept	Algebraic topology
Morse theory on Hilbert manifolds	Concept	Global analysis, analysis on manifolds
Bilateral Z-transform	Definition	Integral transforms, operational calculus
Degree of a projective variety	Definition	Algebraic geometry
Factorization system	Definition	Category theory; homological algebra
Integral quadratic form	Definition	Number theory
Hölder summation	Definition	Sequences, series, summability
Reaction–diffusion system	Concept	Partial differential equations
HNN extension	Definition	Group theory and generalizations
Error-correcting code	Concept	Information and communication theory, circuits