Every idea

Ideas 4351–4500 of 7806.

Name	Kind	Subject
Combinatorial species	Concept	Combinatorics
Fitting subgroup	Definition	Group theory and generalizations
Irreducible matrix	Concept	Linear and multilinear algebra; matrix theory
Stone's theorem on paracompactness of metric spaces	Theorem	General topology
Smale–Hirsch theorem	Theorem	Manifolds and cell complexes
Regular prime	Definition	Number theory
Hilbert's twenty-first problem	Problem	Ordinary differential equations
Eisenstein series as a double series	Example	Sequences, series, summability
Gödel numbering	Definition	Mathematical logic and foundations
Pontryagin's maximum principle	Theorem	Calculus of variations and optimal control; optimization
Unitization	Concept	Functional analysis
Homotopy equivalence	Definition	Algebraic topology
Sum-free set	Concept	Number theory
Reverse mathematics	Concept	Mathematical logic and foundations
Sylvester's determinant identity	Theorem	Linear and multilinear algebra; matrix theory
Quadratic field	Concept	Number theory
LF-space	Concept	Functional analysis
Budan's theorem	Theorem	Real functions
Supersolvable group	Definition	Group theory and generalizations
Weak Lp space	Definition	Functional analysis
Kakutani fixed-point theorem	Theorem	Operator theory
Measure	Definition	Measure and integration
Symbolic power	Definition	Commutative algebra
Normed algebra	Definition	Functional analysis
Waring's problem	Problem	Number theory
Simple function	Concept	Measure and integration
Saturated model	Definition	Mathematical logic and foundations
Sturm–Liouville theory	Concept	Ordinary differential equations
Parallelizable manifold	Concept	Manifolds and cell complexes
Decomposition group	Concept	Number theory
Dirichlet character	Concept	Number theory
Classifying space of a group	Definition	Algebraic topology
Comparison theorem	Theorem	Ordinary differential equations
Kervaire invariant	Definition	Algebraic topology
Hasse's theorem on elliptic curves	Theorem	Number theory
Adapted process	Definition	Probability theory and stochastic processes
Laplacian matrix	Definition	Combinatorics
Basis of a matroid	Definition	Combinatorics
Extraspecial group	Concept	Group theory and generalizations
Artin–Schreier theory	Concept	Field theory and polynomials
Matroid minor	Definition	Combinatorics
Noether normalization lemma	Theorem	Commutative algebra
Out(F_n)	Object	Group theory and generalizations
Transformation semigroup	Concept	Group theory and generalizations
Ramanujan tau function	Definition	Number theory
Flat module	Definition	Commutative algebra
Mazur's lemma	Lemma	Functional analysis
Invariant set	Definition	Ordinary differential equations
Hauptvermutung	Problem	Manifolds and cell complexes
Donsker's theorem	Theorem	Probability theory and stochastic processes
Subnormal operator	Concept	Operator theory
Euler summation	Concept	Sequences, series, summability
Gelfand transform	Definition	Functional analysis
Kolmogorov's normability criterion	Theorem	Functional analysis
Envelope	Concept	Differential geometry
Levin-type transformations	Definition	Numerical analysis
Bishop–Gromov inequality	Theorem	Differential geometry
Moser's trick	Theorem	Differential geometry
Chern–Weil homomorphism	Concept	Differential geometry
Regular open set	Concept	General topology
Fuzzy measure	Definition	Measure and integration
Poincaré–Lindstedt method	Definition	Ordinary differential equations
Cotton tensor	Definition	Differential geometry
Turing jump	Definition	Mathematical logic and foundations
Counterexample to the Markus–Yamabe conjecture	Counterexample	Ordinary differential equations
Injective module	Concept	Commutative algebra
Poincaré disk model	Object	Geometry
Unitization	Definition	Functional analysis
Adjoint of an unbounded operator	Concept	Operator theory
F-space	Concept	Functional analysis
Coercive bilinear form	Concept	Operator theory
Tricolorability	Definition	Manifolds and cell complexes
Polytope combinatorics	Concept	Convex and discrete geometry
Hyperkähler manifold	Concept	Differential geometry
Constant-mean-curvature surface	Definition	Differential geometry
Nuclear space	Definition	Functional analysis
Height of a prime ideal	Concept	Commutative algebra
Faithfully flat module	Definition	Commutative algebra
Gaussian curvature	Definition	Differential geometry
Schrödinger operator	Concept	Ordinary differential equations
Diagonally dominant matrix	Concept	Linear and multilinear algebra; matrix theory
Tracy–Widom distribution	Concept	Probability theory and stochastic processes
Fekete's lemma	Lemma	Sequences, series, summability
Harmonic map	Definition	Global analysis, analysis on manifolds
Holomorphic map between Riemann surfaces	Definition	Functions of a complex variable
McDiarmid's inequality	Theorem	Probability theory and stochastic processes
Schlömilch's generalization of the condensation test	Theorem	Sequences, series, summability
Separably closed field	Concept	Field theory and polynomials
Leray spectral sequence	Theorem	Algebraic topology
van der Waerden conjecture on permanents	Theorem	Linear and multilinear algebra; matrix theory
Lévy's characterization of Brownian motion	Theorem	Probability theory and stochastic processes
Approximation property	Concept	Functional analysis
Resultant	Definition	Commutative algebra
Dirichlet problem	Problem	Potential theory
Holomorphy on Banach spaces	Definition	Functional analysis
f-vector and h-vector	Definition	Combinatorics
Borel summation	Concept	Sequences, series, summability
Free product	Definition	Group theory and generalizations
Projective hierarchy	Concept	Mathematical logic and foundations
Principal bundle	Concept	Algebraic topology
Painlevé property	Concept	Ordinary differential equations
WZ theory	Concept	Combinatorics
Logarithmically convex function	Concept	Real functions
Borel determinacy theorem	Theorem	Mathematical logic and foundations
Boolean-valued model	Definition	Mathematical logic and foundations
Commuting matrices	Concept	Linear and multilinear algebra; matrix theory
Doubling measure	Definition	Measure and integration
Unit disc	Object	Functions of a complex variable
Rational homotopy theory	Concept	Algebraic topology
Lévy–Prokhorov metric	Concept	Probability theory and stochastic processes
4-manifold	Concept	Manifolds and cell complexes
Richardson extrapolation	Definition	Numerical analysis
BK-space	Concept	Functional analysis
Associated graded ring	Concept	Commutative algebra
Crossed product	Concept	Functional analysis
Field norm	Definition	Field theory and polynomials
Almost convergence	Concept	Sequences, series, summability
Fredholm operator	Concept	Operator theory
Besicovitch–Federer projection theorem	Theorem	Measure and integration
Additive energy	Definition	Number theory
Robinson–Schensted–Knuth correspondence	Theorem	Combinatorics
Beta function	Definition	Special functions
Graded ring	Concept	Commutative algebra
Symplectic capacity	Concept	Differential geometry
Generalized Poincaré conjecture	Theorem	Manifolds and cell complexes
Krull domain	Definition	Commutative algebra
Formally smooth map	Concept	Commutative algebra
Homotopy lifting property	Definition	Algebraic topology
Regular open set	Definition	General topology
Quasi-analytic function	Definition	Real functions
Proof that cyclic groups are abelian	Proof	Group theory and generalizations
F-sigma set	Concept	General topology
Total ring of fractions	Definition	Commutative algebra
Word metric	Definition	Group theory and generalizations
Dirichlet series	Concept	Number theory
Homotopy group with coefficients	Concept	Algebraic topology
Hermitian form	Definition	Linear and multilinear algebra; matrix theory
Riemann–Stieltjes integral	Definition	Real functions
G-delta set	Definition	General topology
Lévy process	Concept	Probability theory and stochastic processes
Kolmogorov complexity	Concept	Computer science
Total variation	Concept	Real functions
Principal curvature	Definition	Differential geometry
Artin group	Definition	Group theory and generalizations
Neumann series	Theorem	Operator theory
Cauchy interlacing theorem	Theorem	Linear and multilinear algebra; matrix theory
Paracompact space	Concept	General topology
Shape operator	Definition	Differential geometry
Bergman kernel	Concept	Functions of a complex variable
Tauber's theorem	Theorem	Sequences, series, summability