Every idea

Ideas 21151–21300 of 21839.

Name	Kind	Subject
Club set	Concept	Mathematical logic and foundations
Output controllability	Concept	Systems theory; control
Toric variety	Concept	Algebraic geometry
Instanton	Concept	Differential geometry
Isomorphism	Definition	General algebraic systems
Oriented matroid	Definition	Convex and discrete geometry
Chebyshev nodes	Definition	Numerical analysis
Weierstrass–Enneper parameterization	Theorem	Differential geometry
Uniform space	Definition	General topology
Trace form	Concept	Field theory and polynomials
Smn theorem	Theorem	Mathematical logic and foundations
Vickrey–Clarke–Groves mechanism	Concept	Game theory, economics, finance, and other social and behavioral sciences
Rate of convergence	Concept	Sequences, series, summability
Koszul duality	Definition	Associative rings and algebras
Simplex	Concept	Geometry
Loewner differential equation	Definition	Functions of a complex variable
Exceptional Lie group G2	Example	Topological groups, Lie groups
Hadwiger–Nelson problem	Problem	Combinatorics
Stochastic volatility	Definition	Game theory, economics, finance, and other social and behavioral sciences
Uniform module	Concept	Associative rings and algebras
Sorting network	Definition	Computer science
Regularity of minimizers	Definition	Calculus of variations and optimal control; optimization
Limiting subdifferential	Definition	Calculus of variations and optimal control; optimization
Riesz potential operator	Definition	Operator theory
Group cohomology	Concept	Group theory and generalizations
Method of moments in electromagnetics	Concept	Optics, electromagnetic theory
Contextualism	Concept
Projective object	Concept	Category theory; homological algebra
Inversion in a circle	Concept	Geometry
Arakelov theory	Concept	Algebraic geometry
Proof of the rank inequality for a product of matrices	Proof	Linear and multilinear algebra; matrix theory
Inclusive first-order logic	Concept
Well-formed formulas (wffs)	Proposition
Vincenty's formulae	Concept	Geophysics
Classification of covering spaces	Theorem	Manifolds and cell complexes
Analysis on fractals	Concept	Potential theory
Fractional differential equation	Concept	Ordinary differential equations
BCH code	Concept	Information and communication theory, circuits
Local truncation error	Definition	Numerical analysis
Gelfand–Kirillov dimension	Definition	Associative rings and algebras
Bunimovich stadium	Example	Dynamical systems and ergodic theory
Bose–Einstein condensation	Proposition	Statistical mechanics, structure of matter
Kirby–Siebenmann class	Definition	Manifolds and cell complexes
J-homomorphism	Concept	Algebraic topology
Okubo algebra	Object	Nonassociative rings and algebras
Measurable function	Concept	Measure and integration
Connes embedding problem	Problem	Functional analysis
Laplace's integral for Legendre polynomials	Theorem	Special functions
Thermodynamic stability conditions	Theorem	Classical thermodynamics, heat transfer
Proof that independence means the joint law is the product of the marginals	Proof	Probability theory and stochastic processes
Rayleigh dissipation function	Concept	Mechanics of particles and systems
Morse index theorem for geodesics	Theorem	Global analysis, analysis on manifolds
Doodson numbers	Concept	Geophysics
Electric field	Concept	Optics, electromagnetic theory
Manifold with boundary	Definition	Manifolds and cell complexes
Lying over theorem	Theorem	Commutative algebra
Measure algebra	Concept	Measure and integration
Deceleration parameter	Definition	Relativity and gravitational theory
Symmetric algebra	Definition	Linear and multilinear algebra; matrix theory
Pochhammer symbol	Concept	Combinatorics
Magnetic reconnection	Concept	Fluid mechanics
Calabi–Yau manifold	Definition	Algebraic geometry
Periodicity equation	Concept	Difference and functional equations
t–J model	Example	Statistical mechanics, structure of matter
Infinity	Concept
G-theory	Concept	K-theory
Field of formal Laurent series	Concept	Commutative algebra
Arity	Definition	General algebraic systems
Slice category	Definition	Category theory; homological algebra
Koszul complex	Concept	Commutative algebra
Kolmogorov–Smirnov test	Concept	Statistics
Schubert variety	Concept	Algebraic geometry
Self-concordant function	Definition	Operations research, mathematical programming
Semicontinuity	Definition	General topology
Phylogenetic network	Concept	Biology and other natural sciences
Sard–Smale theorem	Theorem	Global analysis, analysis on manifolds
Zel'dovich approximation	Definition	Astronomy and astrophysics
Chern–Simons form	Definition	Differential geometry
Supermanifold	Concept	Global analysis, analysis on manifolds
Proof that a bounded sequence converges iff its liminf and limsup agree	Proof	Sequences, series, summability
Line segment	Definition	Convex and discrete geometry
Niven's proof of the irrationality of pi	Proof	Number theory
Lieb–Schultz–Mattis theorem	Theorem	Statistical mechanics, structure of matter
Uniserial module	Concept	Associative rings and algebras
Proof of the infinite pigeonhole principle	Proof	Combinatorics
Thin plate spline	Definition	Approximations and expansions
Earth's magnetic field	Concept	Geophysics
Order filter	Concept	Order, lattices, ordered algebraic structures
Proof that the determinant is the product of the eigenvalues by comparing constant terms	Proof	Linear and multilinear algebra; matrix theory
Duality in category theory	Definition	Category theory; homological algebra
Racah polynomials	Definition	Special functions
Implication graph	Concept
Cotangent space of a local ring	Concept	Commutative algebra
Ruin theory	Definition	Game theory, economics, finance, and other social and behavioral sciences
Difference algebra	Concept	Field theory and polynomials
Abel summation	Definition	Sequences, series, summability
Subharmonic function	Concept	Potential theory
The Importance of Synthetic Apriori Propositions to Kant's metaphysics	Proposition
Magnetic vector potential	Definition	Optics, electromagnetic theory
Hawking radiation	Theorem	Relativity and gravitational theory
Frobenius group	Definition	Group theory and generalizations
Lieb–Liniger integral equation	Example	Statistical mechanics, structure of matter
Operator exponential and translation	Proposition	Integral transforms, operational calculus
CR function	Definition	Several complex variables and analytic spaces
Proof that the product of a subgroup and a normal subgroup is a subgroup	Proof	Group theory and generalizations
Axiom A	Concept	Dynamical systems and ergodic theory
Maximal torus	Definition	Topological groups, Lie groups
Prandtl stress function	Concept	Mechanics of deformable solids
Trace class operator	Concept	Operator theory
Principle of maximum entropy	Theorem	Information and communication theory, circuits
Horner's method	Definition	Computer science
Parabolic subgroup	Concept	Topological groups, Lie groups
Positive set theory	Concept
Lumer–Phillips theorem	Theorem	Operator theory
Morrey's inequality	Theorem	Functional analysis
Trace operator	Concept	Functional analysis
Hadamard product	Definition	Linear and multilinear algebra; matrix theory
Suslin rigidity theorem	Theorem	K-theory
Osculating circle	Definition	Differential geometry
Positive cone	Concept	Functional analysis
Littlewood's Tauberian theorem	Theorem	Sequences, series, summability
Axiom of power set	Proposition
Lattice in a Lie group	Definition	Topological groups, Lie groups
Proof that Euclidean domains are principal ideal domains	Proof	Commutative algebra
Spectrum	Definition	Algebraic topology
von Neumann's theory of almost periodic functions on groups	Theorem	Abstract harmonic analysis
Plane curve	Definition	Algebraic geometry
Inverse tangent integral	Definition	Special functions
Weierstrass equation	Concept	Algebraic geometry
Algebraic logic	Concept	Mathematical logic and foundations
Aperiodic set of prototiles	Concept	Convex and discrete geometry
Henselian field	Definition	Field theory and polynomials
Pushout	Definition	Category theory; homological algebra
Current algebra	Concept	Nonassociative rings and algebras
Myers–Steenrod theorem	Theorem	Differential geometry
Invalid deductive argument	Concept
Cubic Hermite spline	Definition	Approximations and expansions
Exact category in the sense of Barr	Definition	Category theory; homological algebra
Beta reduction	Definition	Mathematical logic and foundations
Hairy ball theorem	Theorem	Manifolds and cell complexes
L-theory	Definition	K-theory
Stein space	Concept	Several complex variables and analytic spaces
Thermodynamic cycle	Definition	Classical thermodynamics, heat transfer
Lattice (group)	Definition	Number theory
Summation of families over arbitrary index sets	Definition	Sequences, series, summability
Bass conjecture	Conjecture	K-theory
Condensed set	Definition	Category theory; homological algebra
Little q-Jacobi polynomials	Concept	Special functions
Character of a representation	Definition	Group theory and generalizations
O'Nan–Scott theorem	Theorem	Group theory and generalizations