Every idea

Ideas 7651–7800 of 7806.

Name	Kind	Subject
Semicontinuity	Definition	General topology
Chern–Simons form	Definition	Differential geometry
Cotangent space of a local ring	Concept	Commutative algebra
Difference algebra	Concept	Field theory and polynomials
Abel summation	Definition	Sequences, series, summability
Subharmonic function	Concept	Potential theory
Frobenius group	Definition	Group theory and generalizations
Trace class operator	Concept	Operator theory
Horner's method	Definition	Computer science
Lumer–Phillips theorem	Theorem	Operator theory
Hadamard product	Definition	Linear and multilinear algebra; matrix theory
Osculating circle	Definition	Differential geometry
Littlewood's Tauberian theorem	Theorem	Sequences, series, summability
Spectrum	Definition	Algebraic topology
Algebraic logic	Concept	Mathematical logic and foundations
Henselian field	Definition	Field theory and polynomials
Myers–Steenrod theorem	Theorem	Differential geometry
Hairy ball theorem	Theorem	Manifolds and cell complexes
Lattice (group)	Definition	Number theory
Summation of families over arbitrary index sets	Definition	Sequences, series, summability
Character of a representation	Definition	Group theory and generalizations
O'Nan–Scott theorem	Theorem	Group theory and generalizations
Abstract Wiener space	Definition	Measure and integration
Doob martingale	Example	Probability theory and stochastic processes
Band matrix	Concept	Linear and multilinear algebra; matrix theory
Oracle machine	Concept	Mathematical logic and foundations
3-manifold	Definition	Manifolds and cell complexes
No-retraction theorem	Theorem	Algebraic topology
Current	Definition	Calculus of variations and optimal control; optimization
Four-vertex theorem	Theorem	Differential geometry
Normal Moore space problem	Problem	General topology
Massey product	Concept	Algebraic topology
Girsanov theorem	Theorem	Probability theory and stochastic processes
Monomial ideal	Definition	Commutative algebra
Solvable by radicals	Definition	Field theory and polynomials
Golden–Thompson inequality	Theorem	Linear and multilinear algebra; matrix theory
Sard's theorem	Theorem	Global analysis, analysis on manifolds
Undecidability of the halting problem	Theorem	Mathematical logic and foundations
Curve-shortening flow	Definition	Differential geometry
Tensor decomposition	Definition	Linear and multilinear algebra; matrix theory
Essentially self-adjoint operator	Definition	Operator theory
Finite-rank operator	Concept	Operator theory
Synge's theorem	Theorem	Differential geometry
Monogenic function	Definition	Functions of a complex variable
Martin's axiom	Definition	Mathematical logic and foundations
Christoffel symbols	Definition	Differential geometry
Reeb stability theorem	Theorem	Manifolds and cell complexes
Kervaire invariant problem	Problem	Algebraic topology
Topological manifold	Definition	Manifolds and cell complexes
Hurewicz theorem	Theorem	Algebraic topology
Dehn surgery	Concept	Manifolds and cell complexes
Singular perturbation	Definition	Ordinary differential equations
Curvature form	Concept	Differential geometry
Moment map	Concept	Differential geometry
First and second variation of arc length	Theorem	Differential geometry
Gowers norm	Concept	Number theory
Fundamental groupoid	Concept	Algebraic topology
Cauchy's functional equation	Problem	Difference and functional equations
Bernstein's theorem on monotone functions	Theorem	Real functions
Fuchsian equation	Concept	Ordinary differential equations
Quadratic variation	Definition	Probability theory and stochastic processes
Normal form	Definition	Ordinary differential equations
Universal bundle	Definition	Algebraic topology
Beth number	Definition	Mathematical logic and foundations
Hermite equation	Example	Ordinary differential equations
Regular cardinal	Definition	Mathematical logic and foundations
Varifold	Definition	Calculus of variations and optimal control; optimization
Immersion	Definition	Manifolds and cell complexes
Primary decomposition	Concept	Commutative algebra
Barratt–Priddy–Quillen theorem	Theorem	Algebraic topology
Permutation group	Concept	Group theory and generalizations
Colombeau algebra	Definition	Functional analysis
Barrelled space	Concept	Functional analysis
Fundamental class	Concept	Manifolds and cell complexes
Join	Concept	General topology
Support of a measure	Definition	Measure and integration
Irreducible matrix	Definition	Linear and multilinear algebra; matrix theory
Dirac operator	Definition	Global analysis, analysis on manifolds
Δ-complex	Concept	Algebraic topology
Fundamental groupoid	Definition	Algebraic topology
Kirby calculus	Definition	Manifolds and cell complexes
Lyapunov equation	Definition	Linear and multilinear algebra; matrix theory
Normed field	Concept	Field theory and polynomials
Quasi-isometry	Definition	Group theory and generalizations
Faber polynomials	Definition	Functions of a complex variable
Orlicz space	Definition	Functional analysis
Parallelizable manifold	Definition	Manifolds and cell complexes
Markov chain Monte Carlo	Concept	Numerical analysis
Deligne–Lusztig theory	Concept	Group theory and generalizations
Paracompact space	Definition	General topology
Oscillation theory	Concept	Ordinary differential equations
Graceful tree conjecture	Conjecture	Combinatorics
Green's function	Definition	Ordinary differential equations
Smooth morphism of rings	Definition	Commutative algebra
Relative homotopy group	Concept	Algebraic topology
Scalar curvature	Concept	Differential geometry
C0-semigroup	Definition	Operator theory
Adams' theorem on Hopf invariant one	Theorem	Algebraic topology
Enflo's counterexample to the approximation problem	Counterexample	Functional analysis
Frenet–Serret formulas	Theorem	Differential geometry
Functional differential equation	Concept	Ordinary differential equations
Chevalley group	Definition	Group theory and generalizations
Banach–Zarecki theorem	Theorem	Real functions
Griess algebra	Object	Group theory and generalizations
Bieberbach conjecture	Theorem	Functions of a complex variable
Nest algebra	Concept	Operator theory
Finite-dimensional Hausdorff vector topologies are Euclidean	Theorem	Functional analysis
Radical of an ideal	Definition	Commutative algebra
Volume conjecture	Conjecture	Manifolds and cell complexes
Uniform algebra	Concept	Functional analysis
Control system	Concept	Systems theory; control
Conjugate points	Concept	Differential geometry
Hardy–Littlewood circle method	Concept	Number theory
Donaldson theory	Concept	Manifolds and cell complexes
Legendre transformation	Concept	Real functions
Whitney–Graustein theorem	Theorem	Manifolds and cell complexes
Drazin inverse	Definition	Linear and multilinear algebra; matrix theory
Łoś–Vaught test	Theorem	Mathematical logic and foundations
Feller process	Definition	Probability theory and stochastic processes
Dialectica interpretation	Definition	Mathematical logic and foundations
Conway knot	Example	Manifolds and cell complexes
Lie derivative	Definition	Differential geometry
Lefschetz number	Concept	Algebraic topology
L-infinity space	Concept	Functional analysis
Absolute continuity	Concept	Real functions
Pushforward measure	Definition	Measure and integration
Input-to-state stability	Definition	Systems theory; control
Definable set	Definition	Mathematical logic and foundations
Hindman's theorem	Theorem	Combinatorics
Artinian ring	Definition	Commutative algebra
Montel's theorem	Theorem	Functions of a complex variable
Topology generated by a family of seminorms	Concept	Functional analysis
Numerical linear algebra	Definition	Numerical analysis
Essential supremum	Definition	Measure and integration
Langevin equation	Concept	Probability theory and stochastic processes
Sigma-compact space	Concept	General topology
Statistical convergence	Concept	Sequences, series, summability
Birch and Swinnerton-Dyer conjecture	Conjecture	Number theory
Local martingale	Definition	Probability theory and stochastic processes
Mason–Stothers theorem	Theorem	Number theory
Weak Nullstellensatz	Theorem	Commutative algebra
Newton–Puiseux theorem	Theorem	Commutative algebra
Proof of the cancellation laws	Proof	Group theory and generalizations
Completion of a measure	Definition	Measure and integration
Hellinger–Toeplitz theorem	Theorem	Operator theory
Disjoint union topology	Concept	General topology
Absolute continuity of the Lebesgue integral	Proposition	Measure and integration
Divisible group	Concept	Group theory and generalizations
Transitivity of integrality	Proposition	Commutative algebra
Whitehead tower	Definition	Algebraic topology