Every idea

Ideas 9001–9150 of 10181.

Name	Kind	Subject
Closure of an operator	Concept	Operator theory
Pitchfork bifurcation	Definition	Ordinary differential equations
Sato–Tate conjecture	Theorem	Number theory
Endomorphism ring of a simple module is a division ring	Corollary	Associative rings and algebras
Hankel matrix	Definition	Linear and multilinear algebra; matrix theory
Gauss sum	Definition	Number theory
Gromov–Hausdorff convergence	Definition	Differential geometry
Topological ring	Concept	Associative rings and algebras
Pick matrix	Concept	Functions of a complex variable
Strict hyperbolicity	Definition	Partial differential equations
Elimination theory	Definition	Commutative algebra
Initial algebra	Definition	Category theory; homological algebra
Logicism	Definition	Mathematical logic and foundations
Robinson arithmetic	Definition	Mathematical logic and foundations
Riesz representation theorem	Theorem	Functional analysis
Stokes phenomenon	Concept	Ordinary differential equations
Absolutely free algebra	Concept	General algebraic systems
Kolmogorov's three-series theorem	Theorem	Probability theory and stochastic processes
Atom	Concept	Order, lattices, ordered algebraic structures
Bianchi identities	Theorem	Differential geometry
Locally finite poset	Concept	Order, lattices, ordered algebraic structures
Parallel transport	Concept	Differential geometry
Orientability	Definition	Manifolds and cell complexes
Dual pair	Definition	Functional analysis
Poincaré recurrence theorem	Theorem	Dynamical systems and ergodic theory
Congruence-permutable variety	Definition	General algebraic systems
Torsion tensor	Definition	Differential geometry
Serial ring	Concept	Associative rings and algebras
Quantum logic	Definition	Quantum theory
Cyclotomic extension	Definition	Field theory and polynomials
Finite type invariant	Concept	Manifolds and cell complexes
Étale fundamental group	Definition	Algebraic geometry
Continuous-time Markov chain	Concept	Probability theory and stochastic processes
Deck transformation group	Definition	Manifolds and cell complexes
Čech cohomology	Definition	Algebraic topology
Beurling–Ahlfors transform	Concept	Harmonic analysis on Euclidean spaces
JSJ decomposition	Theorem	Manifolds and cell complexes
Riemann zeta function	Definition	Number theory
Asymmetric simple exclusion process	Example	Probability theory and stochastic processes
Structure theorem for finitely generated modules over a principal ideal domain	Theorem	Commutative algebra
Link	Definition	Manifolds and cell complexes
Summation in topological groups	Concept	Sequences, series, summability
Representation of a quiver	Concept	Associative rings and algebras
Measure problem of Lebesgue	Problem	Measure and integration
Von Neumann–Bernays–Gödel set theory	Definition	Mathematical logic and foundations
Kepler problem	Example	Mechanics of particles and systems
Subdirectly irreducible algebra	Definition	General algebraic systems
Gaussian binomial coefficient	Definition	Combinatorics
Simplicial object	Definition	Category theory; homological algebra
Measurable Riemann mapping theorem	Theorem	Functions of a complex variable
Adjoint functors	Concept	Category theory; homological algebra
Temperley–Lieb algebra	Concept	Associative rings and algebras
Cohen's theorem on Noetherian rings	Theorem	Commutative algebra
Disjoint union of posets	Concept	Order, lattices, ordered algebraic structures
Hadamard three-circle theorem	Theorem	Functions of a complex variable
Primary ideal	Definition	Commutative algebra
Radical ideal	Definition	Commutative algebra
Internal set theory	Concept	Mathematical logic and foundations
Clifford–Klein form	Definition	Manifolds and cell complexes
Fuglede's theorem	Theorem	Operator theory
Radical of a module	Definition	Associative rings and algebras
Kolmogorov continuity theorem	Theorem	Probability theory and stochastic processes
Schur decomposition	Theorem	Linear and multilinear algebra; matrix theory
Compact-open topology	Definition	General topology
Completion of a topological group	Concept	Topological groups, Lie groups
Schwarz–Pick theorem	Theorem	Functions of a complex variable
G-delta set	Concept	General topology
Auslander–Reiten quiver	Definition	Associative rings and algebras
Wiener's Tauberian theorem	Theorem	Abstract harmonic analysis
1 − 1 + 2 − 6 + 24 − 120 + ⋯	Example	Sequences, series, summability
Mapping cylinder	Definition	Algebraic topology
Genus	Definition	Manifolds and cell complexes
Term algebra	Definition	General algebraic systems
Singular values of a compact operator	Definition	Operator theory
Weil's local rigidity theorem	Theorem	Topological groups, Lie groups
Pin group	Example	Topological groups, Lie groups
Homotopy invariance of homology	Theorem	Algebraic topology
Heap	Concept	Group theory and generalizations
Full subcategory	Concept	Category theory; homological algebra
Eilenberg–Zilber theorem	Theorem	Algebraic topology
Mapping cone	Definition	Category theory; homological algebra
No small subgroups	Definition	Topological groups, Lie groups
Solvable Lie group	Definition	Topological groups, Lie groups
Regular local rings are domains	Theorem	Commutative algebra
Lattice congruence	Definition	Order, lattices, ordered algebraic structures
Skolem–Noether theorem	Theorem	Associative rings and algebras
Abel's summation formula	Theorem	Sequences, series, summability
Dynkin system	Concept	Measure and integration
Interpolation space	Definition	Functional analysis
Exponential stability	Definition	Ordinary differential equations
Length of a module	Definition	Commutative algebra
p-adic integer	Concept	Field theory and polynomials
Schur's theorem	Theorem	Combinatorics
Abelian differential	Definition	Functions of a complex variable
Radical extension	Concept	Field theory and polynomials
Residuated mapping	Concept	Order, lattices, ordered algebraic structures
Krull topology	Definition	Field theory and polynomials
Morley's categoricity theorem	Theorem	Mathematical logic and foundations
Perfect closure	Definition	Field theory and polynomials
Simplicial complex	Concept	Combinatorics
Tsen's theorem	Theorem	Field theory and polynomials
Brauer's theorem on induced characters	Theorem	Group theory and generalizations
Martin's axiom	Concept	Mathematical logic and foundations
Stone-type duality for varieties	Definition	General algebraic systems
Sullivan minimal model	Definition	Algebraic topology
Serre's twisting sheaf	Concept	Algebraic geometry
van der Waerden's theorem	Theorem	Combinatorics
Malcev completion	Concept	Topological groups, Lie groups
Connection on a vector bundle	Definition	Differential geometry
Plancherel theorem for abelian groups	Theorem	Abstract harmonic analysis
Grothendieck's local duality	Theorem	Commutative algebra
Term evaluation	Definition	General algebraic systems
Church's theorem on undecidability of first-order logic	Theorem	Mathematical logic and foundations
Type	Definition	Mathematical logic and foundations
Profinite group	Definition	Group theory and generalizations
Krein–Rutman theorem	Theorem	Operator theory
Direct method in the calculus of variations	Definition	Calculus of variations and optimal control; optimization
Operator space	Concept	Operator theory
Morita duality	Definition	Associative rings and algebras
Banach manifold	Definition	Global analysis, analysis on manifolds
n-skeleton	Concept	Manifolds and cell complexes
Cole–Hopf transformation	Concept	Partial differential equations
Universal property	Definition	Category theory; homological algebra
Lyndon–Hochschild–Serre spectral sequence	Theorem	Group theory and generalizations
Fractional Brownian motion	Concept	Probability theory and stochastic processes
BK-space	Definition	Functional analysis
Riemann hypothesis	Conjecture	Number theory
Word metric	Concept	Group theory and generalizations
Dual operator	Concept	Operator theory
Hook length formula	Theorem	Combinatorics
Newlander–Nirenberg theorem	Theorem	Several complex variables and analytic spaces
Cyclotomic extension	Concept	Field theory and polynomials
Order polynomial	Concept	Order, lattices, ordered algebraic structures
Geometric lattice	Concept	Order, lattices, ordered algebraic structures
Markov kernel	Definition	Probability theory and stochastic processes
Residually small variety	Definition	General algebraic systems
Small object argument	Theorem	Category theory; homological algebra
Betti number	Definition	Algebraic topology
von Neumann coordinatization theorem	Theorem	Order, lattices, ordered algebraic structures
Hausdorff content	Concept	Measure and integration
Method of characteristics	Definition	Partial differential equations
Asymptotic analysis	Definition	Approximations and expansions
Day terms	Definition	General algebraic systems
Self-distributive operation	Concept	Group theory and generalizations
Rational homotopy theory	Definition	Algebraic topology
Modular group	Object	Number theory
Wasserstein metric	Concept	Calculus of variations and optimal control; optimization
Ore extension	Concept	Associative rings and algebras
Nonexpansive map	Concept	Operator theory
Perfect graph	Definition	Combinatorics