Every idea

Ideas 17101–17250 of 19838.

Name	Kind	Subject
Love numbers	Definition	Geophysics
Gauge fixing	Concept	Optics, electromagnetic theory
Synchrotron radiation	Concept	Astronomy and astrophysics
Structure theorem for finitely generated modules over a principal ideal domain	Theorem	Commutative algebra
Udwadia–Kalaba equation	Theorem	Mechanics of particles and systems
Boussinesq approximation for buoyancy	Concept	Fluid mechanics
Berlekamp–Massey algorithm	Concept	Information and communication theory, circuits
Link	Definition	Manifolds and cell complexes
Summation in topological groups	Concept	Sequences, series, summability
Prony series	Concept	Mechanics of deformable solids
Forward difference operator	Definition	Difference and functional equations
Representation of a quiver	Concept	Associative rings and algebras
Measure problem of Lebesgue	Problem	Measure and integration
Milne-Thomson circle theorem	Theorem	Fluid mechanics
Principle of maximum entropy in thermodynamics	Fact	Classical thermodynamics, heat transfer
Center of a Lie algebra	Definition	Nonassociative rings and algebras
Morita equivalence of Lie groupoids	Definition	Topological groups, Lie groups
Strange attractor	Definition	Dynamical systems and ergodic theory
Banach analytic space	Concept	Several complex variables and analytic spaces
Von Neumann–Bernays–Gödel set theory	Definition	Mathematical logic and foundations
Kolosov–Muskhelishvili formulas	Theorem	Mechanics of deformable solids
Hour angle	Definition	Astronomy and astrophysics
Charney–Stern theorem	Theorem	Fluid mechanics
Witsenhausen's counterexample	Counterexample	Systems theory; control
Topological cyclic homology	Definition	K-theory
Basel problem via Fourier series	Example	Harmonic analysis on Euclidean spaces
Relay channel	Concept	Information and communication theory, circuits
Fundamental theorem of asset pricing	Theorem	Game theory, economics, finance, and other social and behavioral sciences
Topological insulator	Definition	Statistical mechanics, structure of matter
Kepler problem	Example	Mechanics of particles and systems
Subdirectly irreducible algebra	Definition	General algebraic systems
Neville theta functions	Concept	Special functions
GNSS positioning	Concept	Geophysics
Complementary error function	Concept	Special functions
Gaussian binomial coefficient	Definition	Combinatorics
Representation of a Lie algebra	Concept	Nonassociative rings and algebras
Simplicial object	Definition	Category theory; homological algebra
Measurable Riemann mapping theorem	Theorem	Functions of a complex variable
Adjoint functors	Concept	Category theory; homological algebra
Kutta–Joukowski theorem	Theorem	Fluid mechanics
Temperley–Lieb algebra	Concept	Associative rings and algebras
Cohen's theorem on Noetherian rings	Theorem	Commutative algebra
Disjoint union of posets	Concept	Order, lattices, ordered algebraic structures
Fourier monomial on the circle	Concept	Harmonic analysis on Euclidean spaces
Magnetic field	Definition	Optics, electromagnetic theory
Hadamard three-circle theorem	Theorem	Functions of a complex variable
Primary ideal	Definition	Commutative algebra
Unital	Concept	Geometry
Condorcet paradox	Counterexample	Game theory, economics, finance, and other social and behavioral sciences
Renormalization group	Definition	Statistical mechanics, structure of matter
Triangulation of a point set	Concept	Convex and discrete geometry
Radical ideal	Definition	Commutative algebra
Borda count	Concept	Game theory, economics, finance, and other social and behavioral sciences
Polynomial-time reduction	Concept	Computer science
Reptation	Concept	Statistical mechanics, structure of matter
Internal set theory	Concept	Mathematical logic and foundations
Valuation on convex bodies	Concept	Convex and discrete geometry
Vogan diagram	Definition	Nonassociative rings and algebras
Clifford–Klein form	Definition	Manifolds and cell complexes
Capacity equals transfinite diameter and Chebyshev constant	Theorem	Potential theory
Engel's theorem	Theorem	Nonassociative rings and algebras
Tate's computation of K2 of the rationals	Theorem	K-theory
First law of thermodynamics	Fact	Classical thermodynamics, heat transfer
Split-octonions	Object	Nonassociative rings and algebras
Box–Jenkins method	Definition	Statistics
Motivic cohomology	Concept	K-theory
Fuglede's theorem	Theorem	Operator theory
Locally testable code	Concept	Information and communication theory, circuits
Patched conic approximation	Definition	Mechanics of particles and systems
Fredholm equation of the first kind	Definition	Integral equations
Radical of a module	Definition	Associative rings and algebras
Kolmogorov continuity theorem	Theorem	Probability theory and stochastic processes
Schur decomposition	Theorem	Linear and multilinear algebra; matrix theory
Density matrix	Concept	Quantum theory
Compact-open topology	Definition	General topology
Completion of a topological group	Concept	Topological groups, Lie groups
Schwarz–Pick theorem	Theorem	Functions of a complex variable
Voronoi cell	Concept	Convex and discrete geometry
Cointegration	Concept	Statistics
G-delta set	Concept	General topology
Multibody system	Definition	Mechanics of particles and systems
Z-transform	Definition	Integral transforms, operational calculus
Auslander–Reiten quiver	Definition	Associative rings and algebras
Wiener's Tauberian theorem	Theorem	Abstract harmonic analysis
Tverberg's theorem	Theorem	Convex and discrete geometry
Tensegrity	Definition	Convex and discrete geometry
1 − 1 + 2 − 6 + 24 − 120 + ⋯	Example	Sequences, series, summability
Mapping cylinder	Definition	Algebraic topology
Projection method	Concept	Fluid mechanics
Motivic cohomology	Definition	K-theory
Genus	Definition	Manifolds and cell complexes
Term algebra	Definition	General algebraic systems
Banach–Lie group	Definition	Topological groups, Lie groups
Debye model	Example	Statistical mechanics, structure of matter
Linear complexity of a sequence	Concept	Information and communication theory, circuits
Singular values of a compact operator	Definition	Operator theory
Bessel potential	Concept	Potential theory
Weil's local rigidity theorem	Theorem	Topological groups, Lie groups
Pin group	Example	Topological groups, Lie groups
Tight frame	Concept	Harmonic analysis on Euclidean spaces
Epsilon-net of a set system	Concept	Convex and discrete geometry
Lewy extension theorem	Theorem	Several complex variables and analytic spaces
Strong normalization of simply typed lambda calculus	Theorem	Mathematical logic and foundations
Homotopy invariance of homology	Theorem	Algebraic topology
Quantum electrodynamics	Concept	Quantum theory
Caccioppoli set	Definition	Calculus of variations and optimal control; optimization
Heap	Concept	Group theory and generalizations
Full subcategory	Concept	Category theory; homological algebra
Eilenberg–Zilber theorem	Theorem	Algebraic topology
Mapping cone	Definition	Category theory; homological algebra
Barometric formula	Proposition	Geophysics
No small subgroups	Definition	Topological groups, Lie groups
Causal inference	Concept	Statistics
Polar polytope	Definition	Convex and discrete geometry
Solvable Lie group	Definition	Topological groups, Lie groups
Lerch's uniqueness theorem	Theorem	Integral transforms, operational calculus
Regular local rings are domains	Theorem	Commutative algebra
Nichols plot	Concept	Systems theory; control
Robertson–Schrödinger uncertainty relation	Theorem	Quantum theory
Cyclic redundancy check	Definition	Information and communication theory, circuits
Cubic spline	Concept	Approximations and expansions
Lattice congruence	Definition	Order, lattices, ordered algebraic structures
Initial mass function	Concept	Astronomy and astrophysics
Reynolds decomposition	Concept	Fluid mechanics
Thermodynamics	Definition	Classical thermodynamics, heat transfer
Subgradient method	Definition	Operations research, mathematical programming
Galaxy rotation curve	Concept	Astronomy and astrophysics
Toeplitz extension	Example	Functional analysis
Discrete dipole approximation	Concept	Optics, electromagnetic theory
Quantum vortex	Concept	Fluid mechanics
Trace of an integral operator	Definition	Integral equations
Complex structure on the six-sphere	Problem	Several complex variables and analytic spaces
Skolem–Noether theorem	Theorem	Associative rings and algebras
Factorial experiment	Definition	Statistics
Popov criterion	Theorem	Systems theory; control
Cayley–Klein metric	Definition	Geometry
Hooke's law	Fact	Mechanics of deformable solids
Sitnikov problem	Problem	Mechanics of particles and systems
Lemniscate constant	Object	Special functions
Rolling without slipping	Definition	Mechanics of particles and systems
Abel's summation formula	Theorem	Sequences, series, summability
Dynkin system	Concept	Measure and integration
Perron–Wiener–Brelot solution	Definition	Potential theory
Rigidity of frameworks	Concept	Convex and discrete geometry
Interpolation space	Definition	Functional analysis
Geodynamics	Concept	Geophysics
Binary search	Concept	Computer science
Exponential stability	Definition	Ordinary differential equations
Classical field theory	Concept	Mechanics of particles and systems
Length of a module	Definition	Commutative algebra