Every idea

Ideas 18451–18600 of 19934.

Name	Kind	Subject
Quasi-steady-state approximation	Theorem	Biology and other natural sciences
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
Newtonian limit	Fact	Relativity and gravitational theory
Baker–Campbell–Hausdorff formula	Theorem	Topological groups, Lie groups
Stress deviator tensor	Concept	Mechanics of deformable solids
Mayer–Vietoris sequence	Theorem	Algebraic topology
Eikonal equation	Definition	Partial differential equations
Separable algebra	Concept	Associative rings and algebras
Orthogonality of eigenfunctions of the equation x'' + lambda x = 0 with standard boundary conditions	Theorem	Ordinary differential equations
Column generation	Concept	Operations research, mathematical programming
Stinespring dilation theorem	Theorem	Functional analysis
Balancing domain decomposition	Theorem	Numerical analysis
Frölicher–Nijenhuis bracket	Definition	Global analysis, analysis on manifolds
Hilbert's tenth problem	Theorem	Number theory
Chebotarev's density theorem	Theorem	Number theory
Turing completeness	Definition	Computer science
Lattice	Definition	Order, lattices, ordered algebraic structures
Residually finite algebra	Concept	General algebraic systems
Bangert–Franks theorem on closed geodesics on the sphere	Theorem	Global analysis, analysis on manifolds
Henyey track	Definition	Astronomy and astrophysics
Hardness of approximation	Concept	Computer science
Permanent	Concept	Linear and multilinear algebra; matrix theory
Adjoint state method	Definition	Calculus of variations and optimal control; optimization
Direct limit	Concept	Category theory; homological algebra
Padua points	Example	Approximations and expansions
Hecke operator	Definition	Number theory
Cowling's antidynamo theorem	Theorem	Fluid mechanics
Sub-Gaussian distribution	Concept	Probability theory and stochastic processes
Laguerre–Pólya class	Concept	Functions of a complex variable
F. and M. Riesz theorem	Theorem	Functions of a complex variable
Gödel's incompleteness theorems	Theorem	Mathematical logic and foundations
Adiabatic flame temperature	Definition	Classical thermodynamics, heat transfer
Weyl's theorem on compact perturbations	Theorem	Operator theory
Jacobson radical	Concept	Commutative algebra
Higgs mechanism	Definition	Quantum theory
Logarithmic potential	Definition	Potential theory
Hilbert's fourth problem	Problem	Geometry
Insertion sort	Concept	Computer science
Ol'shanskii's counterexample to the von Neumann conjecture	Counterexample	Abstract harmonic analysis
Matrix Lie group	Definition	Topological groups, Lie groups
Sub-Riemannian geodesic problem	Problem	Differential geometry
Proportional hazards model	Definition	Statistics
Uniform approximation	Concept	Approximations and expansions
Commutative magma	Concept	Group theory and generalizations
Lagrange multipliers for constraints	Concept	Mechanics of particles and systems
Knuth–Morris–Pratt algorithm	Definition	Computer science
Effective resistance	Concept	Potential theory
Hodge conjecture	Conjecture	Algebraic geometry
Metamaterial cloaking	Concept	Optics, electromagnetic theory
Beilinson regulator	Definition	K-theory
Pauli matrices	Object	Quantum theory
Inverse limit	Definition	Category theory; homological algebra
Quasi-Monte Carlo method	Definition	Numerical analysis
Khovanov homology	Concept	Manifolds and cell complexes
Pseudo-spectral method	Concept	Numerical analysis
Strong gravitational lensing	Definition	Astronomy and astrophysics
CAT(0) group	Concept	Group theory and generalizations
Schnirelmann density	Definition	Number theory
Cotlar–Stein lemma	Lemma	Harmonic analysis on Euclidean spaces
Lindelöf's theorem	Theorem	Functions of a complex variable
Euler–Poisson equation for higher derivatives	Concept	Calculus of variations and optimal control; optimization
Incomplete LU factorization	Concept	Numerical analysis
J-homomorphism	Definition	Algebraic topology
Thermal conductivity	Concept	Classical thermodynamics, heat transfer
Laplace–Runge–Lenz vector	Definition	Mechanics of particles and systems
Receiver function	Concept	Geophysics
Index map	Concept	Functional analysis
Harmonic space	Definition	Potential theory
Associated graded ring	Definition	Commutative algebra
Local martingale	Concept	Probability theory and stochastic processes
Kovacic's algorithm	Concept	Ordinary differential equations
Nuclear space	Concept	Functional analysis
Gromoll–Meyer theorem on closed geodesics	Theorem	Global analysis, analysis on manifolds
Prime ring	Definition	Associative rings and algebras
Classification of simple Lie algebras	Theorem	Nonassociative rings and algebras
Probit model	Concept	Statistics
Bühlmann model	Definition	Game theory, economics, finance, and other social and behavioral sciences
Blocking	Concept	Statistics
Quicksort	Definition	Computer science
Model order reduction	Definition	Systems theory; control
Primal algebra	Concept	General algebraic systems
A subgroup of order two in S3 is not normal	Example	Group theory and generalizations
Unary algebra	Concept	General algebraic systems
Watterson estimator	Concept	Statistics
Karnaugh map	Definition	Information and communication theory, circuits
Work hardening	Concept	Mechanics of deformable solids
Affine plane	Definition	Geometry
Simple Lie algebra	Concept	Nonassociative rings and algebras
Fubini's theorem on differentiation	Theorem	Real functions
Metric outer measure	Definition	Measure and integration
Harmonic polynomial	Definition	Potential theory
Branch point	Definition	Functions of a complex variable
Square root of a positive operator	Definition	Operator theory
Nagata ring	Definition	Commutative algebra
Taylor–von Neumann–Sedov blast wave	Example	Fluid mechanics
Brauer–Manin obstruction	Concept	Algebraic geometry
Fox–Wright function	Concept	Special functions
Section of a vector bundle	Definition	Algebraic topology
Face lattice	Example	Convex and discrete geometry
Robin boundary condition for convective cooling	Concept	Classical thermodynamics, heat transfer
Lebesgue–Stieltjes measure	Definition	Measure and integration
Faddeeva function	Definition	Special functions
Modulation space	Definition	Harmonic analysis on Euclidean spaces
Gauss–Laguerre quadrature	Theorem	Numerical analysis
Criss-cross algorithm	Concept	Operations research, mathematical programming
Four-dimensional variational assimilation	Definition	Geophysics
Square root of a matrix	Definition	Linear and multilinear algebra; matrix theory
Best approximation	Definition	Approximations and expansions
Asymptotic scale	Concept	Approximations and expansions
Yield surface	Definition	Mechanics of deformable solids
Anticommutative algebra	Definition	Nonassociative rings and algebras
Siegel–Walfisz theorem	Theorem	Number theory
F-sigma set	Definition	General topology
Brown–Douglas–Fillmore theory	Definition	K-theory
Leech lattice	Object	Number theory
Filippov's existence theorem	Theorem	Calculus of variations and optimal control; optimization
Adjoint integral equation	Concept	Integral equations
Kirchberg–Phillips classification theorem	Theorem	Functional analysis
Elastic metamaterial	Definition	Mechanics of deformable solids
Plus construction	Concept	K-theory
Kontorovich–Lebedev transform	Concept	Integral transforms, operational calculus
Superalgebra	Definition	Nonassociative rings and algebras
Continuous q-Hermite polynomials	Concept	Special functions
Amenable semigroup	Definition	Abstract harmonic analysis
Sturmian word	Example	Computer science
Compressibility	Definition	Classical thermodynamics, heat transfer
Naive set theory	Concept	Mathematical logic and foundations
Hadamard's two-constants theorem	Theorem	Functions of a complex variable
Colimit	Definition	Category theory; homological algebra
Cartan–Kähler theorem	Theorem	Global analysis, analysis on manifolds
Regular semigroup	Concept	Group theory and generalizations
Stability conjecture	Theorem	Dynamical systems and ergodic theory
Plateau–Rayleigh instability	Concept	Fluid mechanics
Colombeau algebra	Concept	Functional analysis
Analytic combinatorics	Definition	Combinatorics
Kähler manifold	Definition	Several complex variables and analytic spaces
Preconditioner	Definition	Numerical analysis
Cluster expansion	Concept	Statistical mechanics, structure of matter
Einstein static universe	Example	Relativity and gravitational theory
Elliptic cohomology	Concept	Algebraic topology
Train track	Concept	Manifolds and cell complexes
Moreau envelope	Definition	Operations research, mathematical programming
Repeated game	Concept	Game theory, economics, finance, and other social and behavioral sciences
Geometric realization	Definition	Algebraic topology
Johnson's rule	Theorem	Operations research, mathematical programming
Linear matrix inequality	Concept	Linear and multilinear algebra; matrix theory