Every idea

Ideas 17851–18000 of 19875.

Name	Kind	Subject
Weak derivative	Definition	Functional analysis
Tube lemma	Lemma	General topology
Term operation	Definition	General algebraic systems
Rees algebra	Concept	Commutative algebra
Frobenius method	Concept	Ordinary differential equations
Stein equation	Definition	Linear and multilinear algebra; matrix theory
Completely distributive lattice	Definition	Order, lattices, ordered algebraic structures
Hamiltonian vector field	Definition	Differential geometry
Free-fall time	Definition	Astronomy and astrophysics
Enumerative geometry	Definition	Algebraic geometry
Besicovitch set of measure zero	Example	Measure and integration
Kaplan–Meier estimator	Definition	Statistics
Stopping time	Definition	Probability theory and stochastic processes
Nielsen–Schreier theorem	Theorem	Group theory and generalizations
Newton–Cotes formulas	Definition	Numerical analysis
Néron model	Definition	Algebraic geometry
Sets of capacity zero	Concept	Potential theory
End and coend	Concept	Category theory; homological algebra
Laplacian on the Sierpiński gasket	Example	Potential theory
Geometric graph	Definition	Combinatorics
Cantor space	Object	General topology
Hill equation	Concept	Biology and other natural sciences
Kelvin transform	Concept	Potential theory
Sieve	Definition	Category theory; homological algebra
Reinhardt domain	Concept	Several complex variables and analytic spaces
Differential dynamic programming	Definition	Calculus of variations and optimal control; optimization
de Rham cohomology	Definition	Global analysis, analysis on manifolds
Fully faithful essentially surjective functor is an equivalence	Theorem	Category theory; homological algebra
Sidon set	Definition	Number theory
Classifying space of a group	Concept	Algebraic topology
Neo-Hookean solid	Example	Mechanics of deformable solids
Joule–Thomson effect	Concept	Classical thermodynamics, heat transfer
Cameron–Martin theorem	Theorem	Measure and integration
Jordan decomposition of a signed measure	Theorem	Measure and integration
Laguerre polynomials	Concept	Special functions
Heat transfer	Definition	Classical thermodynamics, heat transfer
Many-sorted algebra	Concept	General algebraic systems
Kohn Laplacian	Definition	Several complex variables and analytic spaces
Random walk on a group	Concept	Probability theory and stochastic processes
Eilenberg–MacLane space	Definition	Algebraic topology
Range conditions for the Radon transform	Theorem	Integral transforms, operational calculus
Jeans length	Definition	Astronomy and astrophysics
BPST instanton	Object	Quantum theory
Bel–Robinson tensor	Concept	Relativity and gravitational theory
Neyman construction	Definition	Statistics
Heat exchanger theory	Definition	Classical thermodynamics, heat transfer
K-theory	Definition	K-theory
Orlicz space	Concept	Functional analysis
Aberration of light	Proposition	Astronomy and astrophysics
Delzant's theorem on toric manifolds	Theorem	Differential geometry
Angular spectrum method	Concept	Optics, electromagnetic theory
Gamma function has no zeros	Theorem	Special functions
Jacobi ellipsoid	Example	Astronomy and astrophysics
Hyperbolic conservation law	Definition	Partial differential equations
Commutator theory	Definition	General algebraic systems
Smooth manifold	Definition	Global analysis, analysis on manifolds
Wilf–Zeilberger pair	Concept	Special functions
Tits group	Object	Group theory and generalizations
Ternary operation	Concept	General algebraic systems
Penny graph	Definition	Combinatorics
Axiom of determinacy	Definition	Mathematical logic and foundations
Non-equilibrium thermodynamics	Concept	Statistical mechanics, structure of matter
Hyperelliptic curve	Definition	Algebraic geometry
Sparse approximation	Concept	Approximations and expansions
Nonlinear difference equation	Definition	Difference and functional equations
Invariant basis number	Definition	Associative rings and algebras
Vector quantization	Concept	Information and communication theory, circuits
Momentum integral equation	Theorem	Fluid mechanics
Lie algebra of an associative algebra	Example	Nonassociative rings and algebras
Wielandt's theorem	Theorem	Special functions
Complex multiplication	Definition	Number theory
Markov decision process	Concept	Operations research, mathematical programming
Laplace transform method for the heat equation	Example	Integral transforms, operational calculus
Azumaya algebra	Definition	Associative rings and algebras
Geodesy	Concept	Geophysics
Affine term structure model	Concept	Game theory, economics, finance, and other social and behavioral sciences
Non-equilibrium thermodynamics	Definition	Statistical mechanics, structure of matter
Weyl tensor	Definition	Differential geometry
Outer measure	Definition	Measure and integration
Indecomposable module	Definition	Associative rings and algebras
Extreme set	Concept	Convex and discrete geometry
Brane	Definition	Quantum theory
Shirshov–Witt theorem	Theorem	Nonassociative rings and algebras
Gravity assist	Concept	Mechanics of particles and systems
Complex measure	Definition	Measure and integration
Space of null sequences	Example	Functional analysis
Jacobi amplitude	Concept	Special functions
AKLT model	Example	Statistical mechanics, structure of matter
Birkhoff's completeness theorem	Theorem	General algebraic systems
Lagrange points	Object	Mechanics of particles and systems
Harmonic measure as exit distribution	Theorem	Probability theory and stochastic processes
Deterministic finite automaton	Definition	Computer science
Free-air anomaly	Concept	Geophysics
Deformation gradient	Definition	Mechanics of deformable solids
Matrix function	Definition	Linear and multilinear algebra; matrix theory
Realization of a transfer function	Concept	Systems theory; control
Noncommutative harmonic analysis	Concept	Abstract harmonic analysis
Signature	Concept	Mathematical logic and foundations
Quadratic polynomial dynamics	Concept	Dynamical systems and ergodic theory
Chen's theorem	Theorem	Number theory
Shortest path problem	Problem	Operations research, mathematical programming
Van der Pol oscillator	Example	Ordinary differential equations
No-trade theorem	Theorem	Game theory, economics, finance, and other social and behavioral sciences
Isobaric process	Definition	Classical thermodynamics, heat transfer
Sigma-finite measure	Concept	Measure and integration
Generic filter	Concept	Mathematical logic and foundations
Two-body relaxation time	Definition	Astronomy and astrophysics
Fundamental domain	Definition	Topological groups, Lie groups
Cobordism ring	Definition	Manifolds and cell complexes
Hypersingular integral equation	Definition	Integral equations
Hartley transform	Concept	Integral transforms, operational calculus
Ambiguous grammar	Definition	Computer science
Axiom of dependent choice	Concept	Mathematical logic and foundations
Natural boundary	Definition	Functions of a complex variable
Effective temperature	Concept	Astronomy and astrophysics
Lorentz transformation	Concept	Relativity and gravitational theory
Aitken's delta-squared process	Concept	Numerical analysis
Prime radical	Concept	Associative rings and algebras
Stable manifold theorem	Theorem	Ordinary differential equations
Reflection formula for the gamma function	Theorem	Special functions
Rate function	Definition	Probability theory and stochastic processes
Frame-dragging	Proposition	Relativity and gravitational theory
Jacobson topology	Concept	Associative rings and algebras
Hilbert symbol	Concept	Number theory
Bateman transform	Definition	Partial differential equations
Anderson localization	Definition	Statistical mechanics, structure of matter
Mehler–Fock transform	Concept	Integral transforms, operational calculus
Riemann surface	Definition	Functions of a complex variable
Periodic tiling	Concept	Convex and discrete geometry
Necklace splitting theorem	Theorem	Combinatorics
Infinitary operation	Concept	General algebraic systems
Unique solvability of Volterra equations of the second kind	Theorem	Integral equations
Positive cone	Definition	Functional analysis
Post's functional completeness theorem	Theorem	Order, lattices, ordered algebraic structures
Soret effect	Definition	Classical thermodynamics, heat transfer
Dual Radon transform	Definition	Integral transforms, operational calculus
Geodesics in general relativity	Definition	Relativity and gravitational theory
Lüroth problem	Problem	Algebraic geometry
p-adic absolute value	Concept	Field theory and polynomials
Titchmarsh convolution theorem	Theorem	Integral transforms, operational calculus
Projective cover	Concept	Associative rings and algebras
Order polynomial	Definition	Order, lattices, ordered algebraic structures
Inner model	Definition	Mathematical logic and foundations
Completeness in order theory	Definition	Order, lattices, ordered algebraic structures
Internal language	Concept	Mathematical logic and foundations
Lattice	Concept	Order, lattices, ordered algebraic structures
Holonomy	Concept	Differential geometry
Integral current	Definition	Calculus of variations and optimal control; optimization
Quadratic functional equation	Definition	Difference and functional equations
Midpoint method	Proposition	Numerical analysis