Every idea

Ideas 7501–7650 of 7806.

Name	Kind	Subject
Invertible operator	Definition	Operator theory
Percolation threshold	Definition	Probability theory and stochastic processes
Primitive permutation group	Concept	Group theory and generalizations
Robin boundary condition	Definition	Ordinary differential equations
Monotone operator	Concept	Operator theory
Pseudoanalytic function	Concept	Functions of a complex variable
Priority method	Definition	Mathematical logic and foundations
q-Pochhammer symbol	Concept	Combinatorics
Universal cover	Concept	Manifolds and cell complexes
Orders of the elements of S3	Example	Group theory and generalizations
Covering space	Definition	Manifolds and cell complexes
Borg–Marchenko uniqueness theorem	Theorem	Ordinary differential equations
Homotopy principle	Concept	Global analysis, analysis on manifolds
Iwasawa theory	Concept	Number theory
Finitely presented algebra	Definition	Commutative algebra
Curvature form	Definition	Differential geometry
Henstock–Kurzweil integral	Definition	Real functions
Fisher–Tippett–Gnedenko theorem	Theorem	Probability theory and stochastic processes
Evolute	Concept	Differential geometry
Serre's finiteness theorem	Theorem	Algebraic topology
Class	Concept	Mathematical logic and foundations
Sauer–Shelah lemma	Lemma	Combinatorics
Non-atomic measure	Definition	Measure and integration
Sorgenfrey line	Counterexample	General topology
Eigenvalue perturbation	Definition	Linear and multilinear algebra; matrix theory
Schur–Horn theorem	Theorem	Linear and multilinear algebra; matrix theory
Semi-continuity	Definition	Real functions
Structure	Definition	Mathematical logic and foundations
Divisor class group	Definition	Commutative algebra
Injectivity radius	Concept	Differential geometry
Numerical range	Definition	Operator theory
Castelnuovo–Mumford regularity	Concept	Commutative algebra
Hurewicz fibration	Concept	Algebraic topology
de Branges space	Definition	Functional analysis
Lagrange polynomial	Concept	Approximations and expansions
Cheeger constant	Concept	Combinatorics
Exponential map	Concept	Differential geometry
Prime knot	Definition	Manifolds and cell complexes
Infinite compositions of functions	Definition	Sequences, series, summability
Second-order arithmetic	Definition	Mathematical logic and foundations
Continuous and residual spectrum	Definition	Operator theory
Measure with density	Concept	Measure and integration
Germ	Definition	General topology
Stochastic differential equation	Definition	Probability theory and stochastic processes
Branched covering	Concept	Manifolds and cell complexes
Euler's continued fraction formula	Theorem	Sequences, series, summability
Fractional ideal	Concept	Commutative algebra
Ree groups	Object	Group theory and generalizations
Sz.-Nagy's dilation theorem	Theorem	Operator theory
Grushko theorem	Theorem	Group theory and generalizations
Voter model	Example	Probability theory and stochastic processes
Thurston norm	Definition	Manifolds and cell complexes
Schottky group	Concept	Functions of a complex variable
Zariski's lemma	Lemma	Commutative algebra
Buchberger's algorithm	Definition	Commutative algebra
Evolute	Definition	Differential geometry
Hessenberg matrix	Concept	Linear and multilinear algebra; matrix theory
Boundary layer	Concept	Ordinary differential equations
Homology with coefficients	Definition	Algebraic topology
Homotopy groups of spheres	Concept	Algebraic topology
Dini derivative	Definition	Real functions
Going-down theorem	Theorem	Commutative algebra
Mazur–Orlicz theorem	Theorem	Sequences, series, summability
Stationary set	Concept	Mathematical logic and foundations
Hill differential equation	Example	Ordinary differential equations
Bieberbach theorems	Theorem	Group theory and generalizations
Sturm separation theorem	Theorem	Ordinary differential equations
Nagata's example of a Noetherian ring of infinite dimension	Counterexample	Commutative algebra
von Neumann bounded set	Definition	Functional analysis
HNN extension	Concept	Group theory and generalizations
Quasi-analytic function	Concept	Real functions
Limit set	Concept	Dynamical systems and ergodic theory
Excellent ring	Concept	Commutative algebra
Generalized cohomology theory	Definition	Algebraic topology
Isomorphism theorem for measure algebras	Theorem	Measure and integration
Hilbert's Theorem 90	Theorem	Field theory and polynomials
Uniform boundedness principle	Theorem	Functional analysis
Finite field arithmetic	Concept	Field theory and polynomials
Dissipative operator	Definition	Operator theory
Choquet capacity	Definition	Measure and integration
Operator theory	Concept	Operator theory
Quantum invariant of 3-manifolds	Concept	Manifolds and cell complexes
Reflexive operator algebra	Definition	Operator theory
Gromov's compactness theorem	Theorem	Differential geometry
A Dedekind UFD is a PID	Proposition	Commutative algebra
Triangulation	Concept	Manifolds and cell complexes
Poincaré–Lindstedt method	Concept	Ordinary differential equations
Eilenberg–Steenrod axioms	Concept	Algebraic topology
Doob decomposition theorem	Theorem	Probability theory and stochastic processes
Combinatorics on words	Concept	Computer science
WKB approximation	Concept	Ordinary differential equations
Ramification group	Definition	Number theory
Analytic combinatorics	Concept	Combinatorics
Inverse Galois problem	Problem	Field theory and polynomials
Kauffman bracket	Definition	Manifolds and cell complexes
Theorema Egregium	Theorem	Differential geometry
Developable surface	Concept	Differential geometry
Oscillation of a function	Definition	Real functions
Bredon cohomology	Concept	Algebraic topology
Incidence matrix	Definition	Combinatorics
Harnack's inequality	Theorem	Potential theory
Chevalley group	Concept	Group theory and generalizations
Integer factorization	Problem	Number theory
Subfactor	Definition	Functional analysis
1 + 1 + 1 + 1 + ⋯	Example	Sequences, series, summability
Hurwitz zeta function	Definition	Number theory
Locally finite measure	Concept	Measure and integration
Finitely presented module	Definition	Commutative algebra
Commutant	Definition	Functional analysis
Artinian module	Concept	Associative rings and algebras
Observability	Definition	Systems theory; control
Diagonally dominant matrix	Definition	Linear and multilinear algebra; matrix theory
Controllability	Definition	Systems theory; control
Model complete theory	Concept	Mathematical logic and foundations
Functional differential equation	Definition	Ordinary differential equations
Integro-differential equation	Concept	Integral equations
Adapted process	Concept	Probability theory and stochastic processes
Order of an entire function	Definition	Functions of a complex variable
Tarski's undefinability theorem	Theorem	Mathematical logic and foundations
Gaussian binomial coefficient	Concept	Combinatorics
Lambert summation	Definition	Sequences, series, summability
Fuchsian equation	Definition	Ordinary differential equations
Compact quantum group	Definition	Functional analysis
Nevanlinna characteristic	Concept	Functions of a complex variable
Vaught conjecture	Conjecture	Mathematical logic and foundations
Continuous and residual spectrum	Concept	Operator theory
Valuation ring	Definition	Commutative algebra
Topology of uniform convergence	Concept	General topology
Jacobi field	Definition	Differential geometry
Deformation retract	Definition	General topology
Club set	Concept	Mathematical logic and foundations
Instanton	Concept	Differential geometry
Weierstrass–Enneper parameterization	Theorem	Differential geometry
Uniform space	Definition	General topology
Trace form	Concept	Field theory and polynomials
Smn theorem	Theorem	Mathematical logic and foundations
Rate of convergence	Concept	Sequences, series, summability
Loewner differential equation	Definition	Functions of a complex variable
Hadwiger–Nelson problem	Problem	Combinatorics
Classification of covering spaces	Theorem	Manifolds and cell complexes
Fractional differential equation	Concept	Ordinary differential equations
Kirby–Siebenmann class	Definition	Manifolds and cell complexes
J-homomorphism	Concept	Algebraic topology
Measurable function	Concept	Measure and integration
Connes embedding problem	Problem	Functional analysis
Manifold with boundary	Definition	Manifolds and cell complexes
Lying over theorem	Theorem	Commutative algebra
Symmetric algebra	Definition	Linear and multilinear algebra; matrix theory
Field of formal Laurent series	Concept	Commutative algebra
Koszul complex	Concept	Commutative algebra