Every idea

Ideas 8701–8850 of 14183.

Name	Kind	Subject
Quasi-algebraically closed field	Concept	Field theory and polynomials
Admissible function	Concept	Calculus of variations and optimal control; optimization
Hadamard finite part	Concept	Integral equations
Hausdorff moment problem	Problem	Integral transforms, operational calculus
Projection body	Concept	Convex and discrete geometry
Klein–Gordon equation	Definition	Partial differential equations
Formal concept analysis	Concept	Order, lattices, ordered algebraic structures
Bohr compactification	Concept	Topological groups, Lie groups
Quasi-category	Definition	Category theory; homological algebra
Lifting property	Definition	Category theory; homological algebra
Exceptional collection	Concept	Algebraic geometry
Calderón projector	Definition	Partial differential equations
Energy method	Concept	Partial differential equations
Krasner's lemma	Lemma	Field theory and polynomials
Modal logic	Definition	Mathematical logic and foundations
Stiffness matrix	Concept	Numerical analysis
Constructivism	Concept	Mathematical logic and foundations
Cylinder set measure	Concept	Measure and integration
Kirillov orbit method	Concept	Topological groups, Lie groups
Proof methods	Topic	General and overarching topics
Balayage space	Concept	Potential theory
Complete local ring	Concept	Commutative algebra
Mohr–Mascheroni theorem	Theorem	Geometry
Coordinate ring	Concept	Algebraic geometry
System of linear integral equations	Concept	Integral equations
Exact category in the sense of Barr	Concept	Category theory; homological algebra
Laguerre geometry	Concept	Geometry
Yule–Walker equations	Theorem	Statistics
Differential field	Concept	Field theory and polynomials
Connection on a principal bundle	Definition	Differential geometry
Unconditional convergence	Definition	Sequences, series, summability
Linear algebraic group	Concept	Group theory and generalizations
Posner's theorem	Theorem	Associative rings and algebras
Period and index	Definition	Associative rings and algebras
Pro-object	Concept	Category theory; homological algebra
Fisher's equation	Definition	Partial differential equations
Pointwise Kan extension formula	Theorem	Category theory; homological algebra
Poisson summation formula	Theorem	Harmonic analysis on Euclidean spaces
Germ of a smooth function	Definition	Global analysis, analysis on manifolds
Holomorphic fiber bundle	Concept	Several complex variables and analytic spaces
Matrix completion	Problem	Linear and multilinear algebra; matrix theory
Complex analytic variety	Concept	Several complex variables and analytic spaces
p-adic integer	Definition	Field theory and polynomials
Ring of differential operators	Concept	Associative rings and algebras
Trigamma function	Definition	Special functions
Partial differential equation	Concept	Partial differential equations
Lie group action	Definition	Manifolds and cell complexes
Inverse transform	Concept	Integral transforms, operational calculus
Brown representability theorem	Theorem	Algebraic topology
Action-angle coordinates	Definition	Dynamical systems and ergodic theory
Tubular neighborhood theorem	Theorem	Manifolds and cell complexes
Conjugate function	Definition	Harmonic analysis on Euclidean spaces
Hadamard's maximal determinant problem	Problem	Linear and multilinear algebra; matrix theory
Skolem normal form	Concept	Mathematical logic and foundations
Convex independence	Concept	Convex and discrete geometry
Ostrowski's theorem	Theorem	Field theory and polynomials
Contact structure on a jet bundle	Concept	Global analysis, analysis on manifolds
Indeterminate moment problem	Concept	Integral transforms, operational calculus
Slutsky's theorem	Theorem	Probability theory and stochastic processes
Hyperbolic triangle	Concept	Geometry
Free probability	Definition	Functional analysis
d'Alembert's principle	Fact	Mechanics of particles and systems
Bromwich justification of the Heaviside calculus	Concept	Integral transforms, operational calculus
Real analytic manifold	Definition	Several complex variables and analytic spaces
Exponential object	Definition	Category theory; homological algebra
Uniqueness of identity element	Proposition
List coloring	Definition	Combinatorics
Grothendieck topology	Concept	Category theory; homological algebra
Strictly convex space	Concept	Functional analysis
Universal cover	Definition	Manifolds and cell complexes
Fast wavelet transform	Definition	Numerical analysis
Ham sandwich theorem	Theorem	Convex and discrete geometry
Stochastic geometry	Definition	Probability theory and stochastic processes
Schwartz space	Definition	Functional analysis
Analytic semigroup	Definition	Operator theory
Fabry gap theorem	Theorem	Functions of a complex variable
Polarity	Definition	Geometry
Submultiplicative function	Concept	Difference and functional equations
Integral of a non-negative function	Definition	Measure and integration
Steffensen's method	Theorem	Numerical analysis
Nonlinear Schrödinger equation	Concept	Partial differential equations
Filtration of a module	Definition	Commutative algebra
n-term approximation	Concept	Approximations and expansions
Tanaka's formula	Theorem	Probability theory and stochastic processes
Nielsen fixed-point theory	Definition	Algebraic topology
Pythagorean field	Definition	Field theory and polynomials
Fractional Laplacian	Definition	Partial differential equations
Caustic	Definition	Differential geometry
Rosenberg's classification of maximal clones	Theorem	General algebraic systems
Approximately finite-dimensional C*-algebra	Definition	Functional analysis
Homogeneous integral equation	Definition	Integral equations
Sequential space	Definition	General topology
Open immersion	Concept	Algebraic geometry
Appell series	Definition	Special functions
Martin representation theorem	Theorem	Potential theory
Amenable group action	Definition	Abstract harmonic analysis
Kramers–Kronig relations	Theorem	Functions of a complex variable
q-analog	Concept	Combinatorics
Morin singularities	Definition	Manifolds and cell complexes
Dimension theory	Concept	Commutative algebra
Fredholm map	Concept	Global analysis, analysis on manifolds
Latent variable model	Definition	Statistics
Chern–Gauss–Bonnet theorem	Theorem	Differential geometry
Spectral sequence	Concept	Category theory; homological algebra
Congruence-distributive variety	Definition	General algebraic systems
Separable closure	Definition	Field theory and polynomials
Iterative functional equation	Definition	Difference and functional equations
Partial isometry	Concept	Operator theory
Grothendieck topos	Definition	Category theory; homological algebra
Talagrand's concentration inequality	Theorem	Probability theory and stochastic processes
Nagata's criterion for factoriality	Theorem	Commutative algebra
Atiyah–Patodi–Singer index theorem	Theorem	Global analysis, analysis on manifolds
Reeb vector field	Concept	Differential geometry
Algebraic Riccati equation	Concept	Linear and multilinear algebra; matrix theory
Digital topology	Definition	Computer science
Pseudo-Riemannian manifold	Concept	Differential geometry
Algebraic group	Concept	Algebraic geometry
Incompressible surface	Definition	Manifolds and cell complexes
Hartogs figure	Example	Several complex variables and analytic spaces
Higman's lemma	Theorem	Order, lattices, ordered algebraic structures
Going-up theorem	Theorem	Commutative algebra
Linear system of divisors	Concept	Algebraic geometry
Hyperbolic 3-manifold	Concept	Manifolds and cell complexes
Nielsen fixed-point theory	Concept	Algebraic topology
Erdős–Rényi model	Definition	Combinatorics
Prime knot	Concept	Manifolds and cell complexes
von Neumann's minimax theorem	Theorem	Game theory, economics, finance, and other social and behavioral sciences
Lattice of subvarieties	Concept	General algebraic systems
Z-group	Definition	Group theory and generalizations
Behnke–Stein theorem	Theorem	Several complex variables and analytic spaces
Generic matrix algebra	Concept	Associative rings and algebras
Strict Henselization	Concept	Commutative algebra
Curve complex	Definition	Manifolds and cell complexes
Gerstenhaber algebra	Concept	Nonassociative rings and algebras
Numerical methods for ordinary differential equations	Definition	Numerical analysis
Cointegration	Definition	Statistics
Riemann problem	Problem	Partial differential equations
Bang–bang control	Concept	Calculus of variations and optimal control; optimization
Rank-one convexity	Concept	Calculus of variations and optimal control; optimization
Mixed-type equation	Definition	Partial differential equations
Tessellation	Concept	Convex and discrete geometry
Fundamental theorem of projective geometry	Theorem	Geometry
Stiefel–Whitney class	Definition	Manifolds and cell complexes
Toeplitz matrix	Concept	Linear and multilinear algebra; matrix theory
Automatic group	Definition	Group theory and generalizations
Caustic	Concept	Differential geometry
Szegő kernel	Definition	Several complex variables and analytic spaces
Risch algorithm	Definition	Computer science
Levi's extension theorem for meromorphic functions	Theorem	Several complex variables and analytic spaces
Cellular algebra	Definition	Associative rings and algebras