Every idea

Ideas 13051–13200 of 14167.

Name	Kind	Subject
Inverse scattering transform	Definition	Dynamical systems and ergodic theory
Wigner distribution function	Definition	Quantum theory
Diffeomorphism group	Example	Global analysis, analysis on manifolds
Borsuk's conjecture	Counterexample	Convex and discrete geometry
Cobordism	Definition	Manifolds and cell complexes
Estimating equations	Concept	Statistics
Gosper's algorithm	Definition	Special functions
Regularization of ill-posed problems	Concept	Numerical analysis
Rogers–Ramanujan continued fraction	Definition	Number theory
Fujiki class C	Definition	Several complex variables and analytic spaces
Forgetful functor	Concept	Category theory; homological algebra
Pseudovariety	Definition	General algebraic systems
Cartan's test for involutivity	Theorem	Global analysis, analysis on manifolds
Commutative diagram	Concept	Category theory; homological algebra
Lelong number	Concept	Several complex variables and analytic spaces
Cox–de Boor recursion	Theorem	Approximations and expansions
Morlet wavelet	Example	Harmonic analysis on Euclidean spaces
Riemann–Lebesgue lemma	Theorem	Harmonic analysis on Euclidean spaces
Bézout domain	Definition	Commutative algebra
Riesz–Fischer theorem	Theorem	Functional analysis
Schottky group	Definition	Functions of a complex variable
GAGA	Theorem	Several complex variables and analytic spaces
Medial magma	Definition	Group theory and generalizations
Fubini's theorem for series	Theorem	Sequences, series, summability
Jack function	Concept	Combinatorics
Kullback–Leibler divergence	Definition	Information and communication theory, circuits
Simplicial set	Concept	Category theory; homological algebra
Hilbert class field	Concept	Number theory
Method of steepest descent	Definition	Approximations and expansions
Square-integrable kernel	Concept	Integral equations
Shape optimization	Problem	Calculus of variations and optimal control; optimization
Closed immersion	Concept	Algebraic geometry
Eremenko's conjecture	Conjecture	Dynamical systems and ergodic theory
Parabolic and hyperbolic Riemann surfaces	Definition	Functions of a complex variable
Riemann P-symbol	Concept	Special functions
Section of a vector bundle	Concept	Algebraic topology
Wang sequence	Theorem	Algebraic topology
Invariant set	Concept	Ordinary differential equations
Koebe quarter theorem	Theorem	Functions of a complex variable
Borromean rings	Example	Manifolds and cell complexes
Tensor field	Concept	Differential geometry
Poisson integral for the half-space	Theorem	Potential theory
Algebraic number field	Definition	Number theory
Euler's thirty-six officers problem	Problem	Combinatorics
Pseudocomplement	Definition	Order, lattices, ordered algebraic structures
Yoneda Ext and extensions	Theorem	Category theory; homological algebra
Asymptotic stability of linear recurrences	Theorem	Difference and functional equations
Tangent bundle	Concept	Global analysis, analysis on manifolds
Proximity space	Concept	General topology
Brill–Noether theory	Definition	Algebraic geometry
Group representation	Concept	Group theory and generalizations
Vitali set	Counterexample	Measure and integration
Majorization	Definition	Real functions
Fox–Wright function	Definition	Special functions
Lorenz system	Example	Ordinary differential equations
Minkowski–Bouligand dimension	Concept	Measure and integration
Kernel	Definition	Category theory; homological algebra
Locally finite variety	Definition	General algebraic systems
Kakeya needle problem	Problem	Measure and integration
Girth	Definition	Combinatorics
Urysohn integral equation	Concept	Integral equations
Fiber of a morphism	Definition	Algebraic geometry
Cauchy filter	Concept	General topology
Multidimensional Laplace transform	Definition	Integral transforms, operational calculus
Maximal chain	Definition	Order, lattices, ordered algebraic structures
Lie symmetry method	Definition	Ordinary differential equations
Pseudo-Anosov map	Definition	Dynamical systems and ergodic theory
Cut locus	Definition	Differential geometry
Continuous group homomorphism	Definition	Topological groups, Lie groups
Adaptive mesh refinement	Concept	Numerical analysis
Resolvent set	Concept	Operator theory
Borel conjecture	Conjecture	Manifolds and cell complexes
Matrix multiplication exponent	Problem	Computer science
Convex integrand	Concept	Calculus of variations and optimal control; optimization
Maurer–Cartan form	Definition	Topological groups, Lie groups
Convergence along an ultrafilter	Definition	General topology
Schur stable polynomial	Concept	Difference and functional equations
Error-correcting code	Definition	Information and communication theory, circuits
Knot Floer homology	Definition	Manifolds and cell complexes
Symplectic group	Object	Group theory and generalizations
Computability theory	Concept	Mathematical logic and foundations
Dispersive partial differential equation	Definition	Partial differential equations
Kolmogorov–Sinai entropy	Concept	Dynamical systems and ergodic theory
Fractional iteration	Definition	Difference and functional equations
Large cardinal	Concept	Mathematical logic and foundations
Wolff potential	Definition	Potential theory
Anosov diffeomorphism	Definition	Dynamical systems and ergodic theory
Schreier coset graph	Definition	Group theory and generalizations
Horn hypergeometric series	Concept	Special functions
Analytic capacity	Definition	Functions of a complex variable
Synthetic differential geometry	Definition	Geometry
Stable ∞-category	Concept	Category theory; homological algebra
Regularization of ill-posed problems	Definition	Numerical analysis
Information-based complexity	Definition	Numerical analysis
Complex torus	Definition	Algebraic geometry
Mellin's inverse formula	Theorem	Integral transforms, operational calculus
Separated morphism	Concept	Algebraic geometry
Formally real field	Concept	Field theory and polynomials
Ordered vector space	Definition	Functional analysis
Gelfand–Levitan–Marchenko equation	Concept	Ordinary differential equations
Semilinear PDE	Definition	Partial differential equations
Lie symmetry method	Concept	Ordinary differential equations
Hearing the shape of a drum	Problem	Global analysis, analysis on manifolds
Exotic R4	Object	Manifolds and cell complexes
Center manifold	Concept	Ordinary differential equations
Quadratic variation	Concept	Probability theory and stochastic processes
Calabi–Weil rigidity	Corollary	Differential geometry
Tanh-sinh quadrature	Proposition	Numerical analysis
Schur's lemma	Lemma	Associative rings and algebras
Mittag-Leffler's theorem	Theorem	Functions of a complex variable
Superharmonic function	Concept	Potential theory
Lelong class	Concept	Several complex variables and analytic spaces
Compositum of fields	Definition	Field theory and polynomials
Rees matrix semigroup	Concept	Group theory and generalizations
Colorful Carathéodory theorem	Theorem	Convex and discrete geometry
Milnor fibre is a bouquet of spheres	Theorem	Several complex variables and analytic spaces
Laplace transform of the exponential function	Example	Integral transforms, operational calculus
Algorithmic randomness	Definition	Mathematical logic and foundations
Nörlund mean	Concept	Sequences, series, summability
Cut locus	Concept	Differential geometry
Givens rotation	Definition	Numerical analysis
Kähler manifold	Concept	Several complex variables and analytic spaces
Abel–Dini theorem	Theorem	Sequences, series, summability
Differentiable curve	Definition	Differential geometry
Finite ring	Concept	Associative rings and algebras
Additive Schwarz method	Theorem	Numerical analysis
Exponential functions on semigroups	Definition	Difference and functional equations
Fourier–Bessel series	Definition	Harmonic analysis on Euclidean spaces
Localization at a prime ideal	Concept	Commutative algebra
Rough path	Concept	Probability theory and stochastic processes
Harmonic map heat flow	Definition	Global analysis, analysis on manifolds
Upper half-plane	Object	Functions of a complex variable
Inner-outer factorization	Theorem	Functions of a complex variable
Envelope of holomorphy	Concept	Several complex variables and analytic spaces
Spectral theorem for bounded normal operators	Theorem	Operator theory
Robbins conjecture	Theorem	Order, lattices, ordered algebraic structures
Rack and quandle	Concept	Manifolds and cell complexes
Multiplier ideal	Definition	Algebraic geometry
Tangential Cauchy–Riemann equations	Concept	Several complex variables and analytic spaces
Integrable function	Concept	Measure and integration
Finite difference method	Concept	Numerical analysis
Archimedean solid	Object	Geometry
Artin's theorem on fixed fields	Theorem	Field theory and polynomials
Bondy's theorem	Theorem	Combinatorics
Lie algebra of a compact group is reductive	Theorem	Topological groups, Lie groups
Marsden–Weinstein reduction	Definition	Differential geometry
Summability method	Definition	Sequences, series, summability
Chern–Simons form	Concept	Differential geometry
Integral element	Definition	Commutative algebra
Jensen inequality as a functional inequality	Proposition	Difference and functional equations