Every idea

Ideas 10201–10350 of 11985.

Name	Kind	Subject
Tracy–Widom distribution	Definition	Probability theory and stochastic processes
Euler–Gauss limit formula	Theorem	Special functions
Hypoelliptic operator	Definition	Partial differential equations
Lefschetz principle	Theorem	Mathematical logic and foundations
Hellinger distance	Concept	Statistics
Golay code	Object	Information and communication theory, circuits
Hom functor	Definition	Category theory; homological algebra
Group algebra	Definition	Group theory and generalizations
Null-homotopic map	Concept	Algebraic topology
Tensor product of modules	Definition	Commutative algebra
Comparability graph	Definition	Combinatorics
Grothendieck universe	Concept	Mathematical logic and foundations
Tensor rank	Definition	Linear and multilinear algebra; matrix theory
Left-invariant vector field	Concept	Topological groups, Lie groups
Laplace's equation	Definition	Partial differential equations
Expectation–maximization algorithm	Definition	Statistics
Generalized Fourier series	Concept	Harmonic analysis on Euclidean spaces
Whitney immersion theorem	Theorem	Manifolds and cell complexes
Wang's finiteness theorem	Theorem	Topological groups, Lie groups
Delay differential equation	Definition	Ordinary differential equations
Hasse principle	Definition	Number theory
Non-Euclidean geometry	Concept	Geometry
Segre's theorem	Theorem	Geometry
Topological group structure of a vector space	Concept	Functional analysis
Spherical geometry	Concept	Geometry
Auslander–Buchsbaum formula	Theorem	Commutative algebra
Carleson measure	Concept	Functions of a complex variable
Hadamard product	Concept	Linear and multilinear algebra; matrix theory
Gaussian curvature	Concept	Differential geometry
Abelian extension	Definition	Field theory and polynomials
Ultrafilter	Definition	General topology
Hotelling's T-squared distribution	Definition	Statistics
Weak homotopy equivalence	Definition	Algebraic topology
String diagram	Definition	Category theory; homological algebra
Braid group	Definition	Group theory and generalizations
Convergence of Fourier series	Definition	Harmonic analysis on Euclidean spaces
Polynomial interpolation	Concept	Approximations and expansions
Bäcklund transform	Concept	Dynamical systems and ergodic theory
Beth number	Concept	Mathematical logic and foundations
Complete set of orthogonal idempotents	Concept	Associative rings and algebras
Pitman–Koopman–Darmois theorem	Theorem	Statistics
Inner regular measure	Definition	Measure and integration
Hausdorff dimension	Concept	Measure and integration
Monomorphism	Definition	Category theory; homological algebra
Elliptic boundary value problem	Definition	Partial differential equations
Betti number	Concept	Algebraic topology
Tight frame	Definition	Harmonic analysis on Euclidean spaces
Poisson regression	Concept	Statistics
Boolean prime ideal theorem	Theorem	Mathematical logic and foundations
Krull dimension of a poset	Definition	Order, lattices, ordered algebraic structures
Inductive dimension	Definition	General topology
Calabi–Yau manifold	Concept	Algebraic geometry
Moise's theorem	Theorem	Manifolds and cell complexes
Surface of general type	Concept	Algebraic geometry
Cusp form	Definition	Number theory
Non-atomic measure	Concept	Measure and integration
Trigonometric interpolation	Concept	Harmonic analysis on Euclidean spaces
Isomonodromic deformation	Definition	Ordinary differential equations
Kummer–Artin–Schreier–Witt theory	Definition	Field theory and polynomials
Hadwiger covering conjecture	Conjecture	Convex and discrete geometry
Large sieve	Definition	Number theory
Valuation	Definition	Field theory and polynomials
Lindelöf space	Concept	General topology
Strict partial order	Definition	Order, lattices, ordered algebraic structures
Linearly disjoint extensions	Definition	Field theory and polynomials
Deformation theory	Concept	Algebraic geometry
Burkholder–Davis–Gundy inequality	Theorem	Probability theory and stochastic processes
Rational point	Concept	Algebraic geometry
Crossing number	Concept	Manifolds and cell complexes
Universal covering group	Concept	Topological groups, Lie groups
Functor of points	Concept	Algebraic geometry
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
Spherical trigonometry	Concept	Geometry
Sequential probability ratio test	Concept	Statistics
Newton polytope	Definition	Algebraic geometry
Minkowski addition	Concept	Convex and discrete geometry
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
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
Hadamard's example of ill-posedness	Counterexample	Partial differential equations
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
Subalgebra lattice	Concept	General algebraic systems
Band matrix	Definition	Linear and multilinear algebra; matrix theory
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
Associative quotient of a magma	Concept	Group theory and generalizations
Maximal compact subgroup	Concept	Topological groups, Lie groups
Mean curvature	Definition	Differential geometry
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
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
Differential field	Definition	Field theory and polynomials
Substitution tiling	Definition	Dynamical systems and ergodic theory
Primal algebra	Definition	General algebraic systems
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
Doléans-Dade exponential	Definition	Probability theory and stochastic processes
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
Baum–Welch algorithm	Definition	Statistics
Modular curve	Concept	Number theory
Ambrose–Singer theorem	Theorem	Differential geometry
n-sphere	Object	Manifolds and cell complexes
Right adjoints preserve limits	Theorem	Category theory; homological algebra
Descartes' rule of signs	Theorem	Real functions
Gorenstein ring	Concept	Commutative algebra
Hodges–Lehmann estimator	Concept	Statistics