Every idea

Ideas 17401–17550 of 19875.

Name	Kind	Subject
Clausius statement of the second law	Fact	Classical thermodynamics, heat transfer
Tollmien–Schlichting wave	Definition	Fluid mechanics
Self-distributive operation	Concept	Group theory and generalizations
Tellegen's theorem	Theorem	Information and communication theory, circuits
Lemaître–Tolman metric	Example	Relativity and gravitational theory
Rational homotopy theory	Definition	Algebraic topology
Modular group	Object	Number theory
Independent component analysis	Definition	Statistics
Differentiation in the transform variable	Theorem	Integral transforms, operational calculus
Emissivity	Concept	Classical thermodynamics, heat transfer
Brody's lemma	Theorem	Several complex variables and analytic spaces
Curvelet	Concept	Harmonic analysis on Euclidean spaces
Wasserstein metric	Concept	Calculus of variations and optimal control; optimization
Congestion game	Concept	Game theory, economics, finance, and other social and behavioral sciences
Isogeometric analysis	Definition	Numerical analysis
Ore extension	Concept	Associative rings and algebras
Geodesic flow	Example	Dynamical systems and ergodic theory
Nonexpansive map	Concept	Operator theory
Enthalpy	Definition	Classical thermodynamics, heat transfer
Nonparametric statistics	Concept	Statistics
Perfect graph	Definition	Combinatorics
Cyclic extension	Concept	Field theory and polynomials
Complete Boolean algebra	Definition	Order, lattices, ordered algebraic structures
Ultraproduct	Definition	Mathematical logic and foundations
Bockstein homomorphism	Definition	Algebraic topology
Loop quantum gravity	Definition	Relativity and gravitational theory
Hyers' theorem	Theorem	Difference and functional equations
The odd integers are not a subgroup of the integers	Example	Group theory and generalizations
Minimal period	Concept	Dynamical systems and ergodic theory
Optical aberration	Concept	Optics, electromagnetic theory
Anisotropic heat conduction	Definition	Classical thermodynamics, heat transfer
Signed measure	Concept	Measure and integration
Redlich–Kwong equation of state	Definition	Classical thermodynamics, heat transfer
Smooth structure	Definition	Manifolds and cell complexes
Legendre transformation of thermodynamic potentials	Definition	Classical thermodynamics, heat transfer
Bourgain's dimension bound for harmonic measure	Theorem	Potential theory
Pseudo-arc	Example	General topology
Nambu mechanics	Definition	Mechanics of particles and systems
Surface	Concept	Manifolds and cell complexes
Vector optimization	Definition	Operations research, mathematical programming
Bifurcation set	Definition	Global analysis, analysis on manifolds
Jury stability criterion	Theorem	Systems theory; control
Revised simplex method	Definition	Operations research, mathematical programming
Laplace transform of an integral	Proposition	Integral transforms, operational calculus
Measure with density	Definition	Measure and integration
Stone-type duality for varieties	Concept	General algebraic systems
Artstein's theorem	Theorem	Systems theory; control
Period map	Definition	Several complex variables and analytic spaces
Huntington's axioms	Definition	Order, lattices, ordered algebraic structures
Ericksen's problem of universal deformations	Problem	Mechanics of deformable solids
Weaire–Phelan structure	Example	Convex and discrete geometry
List coloring	Concept	Combinatorics
Galois' theorem on solvability	Theorem	Field theory and polynomials
Algebraic set	Concept	Algebraic geometry
Seidel aberrations	Concept	Optics, electromagnetic theory
f-ring	Concept	Order, lattices, ordered algebraic structures
Shrinkage estimator	Definition	Statistics
Gegenbauer transform	Definition	Integral transforms, operational calculus
Fourier transform on locally compact abelian groups	Concept	Abstract harmonic analysis
Master equation	Concept	Statistical mechanics, structure of matter
Artinian module	Definition	Associative rings and algebras
Riesz basis	Definition	Harmonic analysis on Euclidean spaces
Completely monotone function	Concept	Real functions
Lindeberg's condition	Concept	Probability theory and stochastic processes
Risch algorithm	Concept	Computer science
Blasius boundary layer	Example	Fluid mechanics
Askey–Gasper inequality	Theorem	Special functions
Zeta function regularization	Concept	Number theory
Opposite ring	Definition	Associative rings and algebras
Littlewood's L1 norm conjecture	Theorem	Harmonic analysis on Euclidean spaces
Radon transform	Concept	Integral transforms, operational calculus
Köthe–Toeplitz dual	Concept	Functional analysis
Hom functor	Concept	Category theory; homological algebra
Graph embedding	Definition	Combinatorics
Bing–Borsuk conjecture	Conjecture	Manifolds and cell complexes
Real K-theory KO	Definition	Algebraic topology
Perfectly normal space	Concept	General topology
Normal shock relations	Proposition	Fluid mechanics
Thompson groups	Object	Group theory and generalizations
Torsion submodule	Definition	Commutative algebra
Debye length	Definition	Statistical mechanics, structure of matter
Reductive group	Definition	Group theory and generalizations
Fixation probability	Definition	Biology and other natural sciences
Distributed source coding	Concept	Information and communication theory, circuits
Pancharatnam–Berry phase	Concept	Optics, electromagnetic theory
Absolute geometry	Concept	Geometry
Submanifold	Concept	Global analysis, analysis on manifolds
Observable	Definition	Quantum theory
Volterra integral equation	Definition	Integral equations
Beam theory	Definition	Mechanics of deformable solids
Deformation of complex structure	Concept	Several complex variables and analytic spaces
Angular momentum operator	Concept	Quantum theory
State function	Definition	Classical thermodynamics, heat transfer
Azumaya algebra	Concept	Associative rings and algebras
Ridders' method	Proposition	Numerical analysis
Acceleration	Definition	Mechanics of particles and systems
Condenser capacity	Definition	Potential theory
Greedy algorithm	Definition	Computer science
Closed operator	Concept	Operator theory
Pesin theory	Definition	Dynamical systems and ergodic theory
Complex analytic variety	Definition	Several complex variables and analytic spaces
Gibbs phenomenon	Concept	Harmonic analysis on Euclidean spaces
Thom–Mather stratified space	Definition	Global analysis, analysis on manifolds
Laman graph	Definition	Convex and discrete geometry
Multipole expansion	Definition	Optics, electromagnetic theory
Reptation	Definition	Statistical mechanics, structure of matter
Exposed point	Concept	Convex and discrete geometry
Upper-convected Maxwell model	Example	Fluid mechanics
Heat equation	Definition	Partial differential equations
Irreducible representation	Definition	Group theory and generalizations
Fuchsian group	Concept	Group theory and generalizations
Horseshoe lemma	Lemma	Category theory; homological algebra
Linear programming	Concept	Operations research, mathematical programming
Four-velocity	Definition	Relativity and gravitational theory
Nyström method	Theorem	Numerical analysis
Densely defined operator	Definition	Operator theory
Extreme point	Definition	Functional analysis
Wandering set	Concept	Dynamical systems and ergodic theory
Function approximation	Concept	Approximations and expansions
Algebraic stack	Concept	Algebraic geometry
Conjugate points	Definition	Differential geometry
Model checking	Concept	Computer science
Reinhardt domain	Definition	Several complex variables and analytic spaces
Brzozowski derivative	Definition	Computer science
Algebraic stack	Definition	Algebraic geometry
Quantum complexity class BQP	Concept	Computer science
Heat equation	Concept	Partial differential equations
Bernstein–Kushnirenko theorem	Theorem	Algebraic geometry
Romberg's method	Concept	Numerical analysis
Moduli space of instantons	Object	Global analysis, analysis on manifolds
Logarithmic integral	Concept	Special functions
Kriging	Concept	Statistics
Infinitesimal generator of a Markov process	Concept	Probability theory and stochastic processes
Oldroyd-B model	Example	Fluid mechanics
Algebraic combinatorics	Concept	Combinatorics
Pexider equation	Definition	Difference and functional equations
Gillespie algorithm	Concept	Numerical analysis
Associated Legendre polynomials	Concept	Special functions
Featherstone's algorithm	Concept	Mechanics of particles and systems
Positive-definite function	Definition	Harmonic analysis on Euclidean spaces
Control variates	Theorem	Numerical analysis
Proj construction	Definition	Algebraic geometry
Birkhoff's theorem (relativity)	Theorem	Relativity and gravitational theory
Geometric integrator	Concept	Dynamical systems and ergodic theory
Annihilator	Definition	Commutative algebra
Line segment	Concept	Convex and discrete geometry
Torsion-free group	Definition	Group theory and generalizations
Sverdrup balance	Proposition	Geophysics
Periodic table of topological insulators	Theorem	Statistical mechanics, structure of matter
Cusp catastrophe	Example	Global analysis, analysis on manifolds