Every idea

Ideas 8101–8250 of 10181.

Name	Kind	Subject
Discrete spectrum	Concept	Operator theory
Hausdorff summation	Concept	Sequences, series, summability
Identity	Concept	General algebraic systems
Semihereditary ring	Definition	Associative rings and algebras
Non-measurable set	Concept	Measure and integration
Sub-Gaussian distribution	Definition	Probability theory and stochastic processes
Petersen's theorem	Theorem	Combinatorics
q-derivative	Concept	Combinatorics
Littlewood subordination theorem	Theorem	Functions of a complex variable
Crossed product algebra	Definition	Associative rings and algebras
Quasisymmetric map	Definition	Functions of a complex variable
Pentagonal number theorem	Theorem	Number theory
Noetherian module	Definition	Commutative algebra
Airy equation	Example	Ordinary differential equations
Strongly minimal theory	Concept	Mathematical logic and foundations
Hardy space	Concept	Functions of a complex variable
Faithful module	Definition	Associative rings and algebras
Slice knot	Definition	Manifolds and cell complexes
Krull dimension of a noncommutative ring	Concept	Associative rings and algebras
Computable set	Concept	Mathematical logic and foundations
Cole–Hopf transformation	Definition	Partial differential equations
Cauchy–Riemann operator	Concept	Several complex variables and analytic spaces
Reproducing kernel Hilbert space	Definition	Functional analysis
Real algebraic geometry	Concept	Algebraic geometry
Hankel matrix	Concept	Linear and multilinear algebra; matrix theory
Calculus of variations	Concept	Calculus of variations and optimal control; optimization
Sheaf cohomology	Concept	Algebraic geometry
Symplectic vector space	Concept	Linear and multilinear algebra; matrix theory
Classical group	Definition	Group theory and generalizations
Kullback–Leibler divergence	Concept	Information and communication theory, circuits
Equivalence of Boolean rings and Boolean algebras	Theorem	Order, lattices, ordered algebraic structures
Natural boundary	Concept	Functions of a complex variable
Infinitary logic	Concept	Mathematical logic and foundations
Pro-object	Definition	Category theory; homological algebra
Binary quadratic form	Definition	Number theory
Measure	Concept	Measure and integration
Separation of variables	Definition	Ordinary differential equations
Biharmonic equation	Definition	Potential theory
Stochastic partial differential equation	Concept	Probability theory and stochastic processes
Seiberg–Witten invariants	Concept	Manifolds and cell complexes
Subobject classifier	Definition	Category theory; homological algebra
Paratopological group	Definition	Topological groups, Lie groups
Alexander's theorem on closed braids	Theorem	Manifolds and cell complexes
Euler–Lagrange equation	Concept	Calculus of variations and optimal control; optimization
Vector measure	Concept	Measure and integration
Noncommutative geometry	Concept	Global analysis, analysis on manifolds
Basic open set	Definition	Algebraic geometry
Janko groups	Object	Group theory and generalizations
Von Neumann algebra	Concept	Functional analysis
Amoeba	Concept	Algebraic geometry
Beurling–Ahlfors transform	Definition	Harmonic analysis on Euclidean spaces
Riemannian distance	Definition	Differential geometry
Fractional Brownian motion	Definition	Probability theory and stochastic processes
Quasi-coherent sheaf	Definition	Algebraic geometry
Killing vector field	Definition	Differential geometry
Clone	Concept	General algebraic systems
Premeasure	Concept	Measure and integration
Lindelöf hypothesis	Conjecture	Number theory
Partial differential equation	Definition	Partial differential equations
Sublattice	Concept	Order, lattices, ordered algebraic structures
Transport equation	Concept	Partial differential equations
Doubling on the integers is not an isomorphism	Example	Group theory and generalizations
Faber polynomials	Concept	Functions of a complex variable
Matroid	Definition	Combinatorics
Weak ordering	Concept	Order, lattices, ordered algebraic structures
Small cancellation theory	Definition	Group theory and generalizations
Unknotting number	Concept	Manifolds and cell complexes
Antipode	Definition	Associative rings and algebras
Signature	Definition	Mathematical logic and foundations
Grothendieck universe	Definition	Mathematical logic and foundations
Levy–Desplanques theorem	Theorem	Linear and multilinear algebra; matrix theory
Perfect closure	Concept	Field theory and polynomials
Cyclic extension	Definition	Field theory and polynomials
Atlas	Definition	Manifolds and cell complexes
Erdős–Hajnal conjecture	Conjecture	Combinatorics
Countable additivity	Definition	Measure and integration
Matroid	Concept	Combinatorics
Happy ending problem	Problem	Convex and discrete geometry
Uniformly convex space	Definition	Functional analysis
Normal function	Definition	Mathematical logic and foundations
Morley rank	Definition	Mathematical logic and foundations
Normal basis theorem	Theorem	Field theory and polynomials
Monoidal functor	Concept	Category theory; homological algebra
Dold–Kan correspondence	Theorem	Category theory; homological algebra
Universally catenary ring	Definition	Commutative algebra
Semiring of sets	Concept	Measure and integration
Positive mass theorem	Theorem	Differential geometry
Finitely complete category	Concept	Category theory; homological algebra
Spinor bundle	Concept	Differential geometry
Hilbert space	Definition	Functional analysis
Projective algebra	Concept	General algebraic systems
Sporadic group	Concept	Group theory and generalizations
Noncommutative torus	Example	Functional analysis
One-relator group	Definition	Group theory and generalizations
Systolic geometry	Concept	Differential geometry
Relational clone	Definition	General algebraic systems
Locally presentable category	Concept	Category theory; homological algebra
Epimorphism	Definition	Category theory; homological algebra
Isomorphism	Concept	General algebraic systems
Hörmander's condition	Definition	Partial differential equations
Sequent calculus	Definition	Mathematical logic and foundations
Lagrangian submanifold	Definition	Differential geometry
Pullback	Concept	Category theory; homological algebra
Semiring	Definition	Associative rings and algebras
Schwartz impossibility theorem	Theorem	Functional analysis
SL(2,R)	Example	Topological groups, Lie groups
Category theory	Definition	Category theory; homological algebra
Pointed space	Definition	Algebraic topology
Complemented subspace	Concept	Functional analysis
Spinor bundle	Definition	Differential geometry
Tridiagonal matrix	Definition	Linear and multilinear algebra; matrix theory
Intuitionistic logic	Concept	Mathematical logic and foundations
Category theory	Concept	Category theory; homological algebra
Hausdorff measure	Concept	Measure and integration
Khinchin integral	Concept	Real functions
Dual of Lp	Theorem	Functional analysis
Axiom of constructibility	Definition	Mathematical logic and foundations
Direct limit of algebras	Definition	General algebraic systems
Foundations of mathematics	Definition	Mathematical logic and foundations
Semi-local ring	Definition	Commutative algebra
Asymptotic analysis	Concept	Approximations and expansions
Duhamel's principle	Theorem	Ordinary differential equations
Legendrian submanifold	Concept	Differential geometry
Fatou's theorem	Theorem	Functions of a complex variable
Domain theory	Concept	Order, lattices, ordered algebraic structures
Unary operation	Concept	General algebraic systems
Topology of uniform convergence	Definition	General topology
Incomparability theorem	Theorem	Commutative algebra
Linear extension	Definition	Order, lattices, ordered algebraic structures
Vandermonde matrix	Concept	Linear and multilinear algebra; matrix theory
Grothendieck topology	Definition	Category theory; homological algebra
K3 surface	Concept	Algebraic geometry
Dunford–Pettis theorem	Theorem	Functional analysis
Dehn surgery	Definition	Manifolds and cell complexes
Type theory	Concept	Mathematical logic and foundations
Littlewood–Richardson rule	Theorem	Combinatorics
Dehn function	Concept	Group theory and generalizations
Fredholm operator	Definition	Operator theory
Riemannian Penrose inequality	Theorem	Differential geometry
Galois connection	Concept	Order, lattices, ordered algebraic structures
Hahn–Mazurkiewicz theorem	Theorem	General topology
Direct limit of rings	Concept	Associative rings and algebras
Riemannian metric	Concept	Differential geometry
Property P conjecture	Theorem	Manifolds and cell complexes
Pushout	Concept	Category theory; homological algebra
Young tableau	Concept	Combinatorics
Cartesian closed category	Definition	Category theory; homological algebra
Equational logic	Definition	General algebraic systems
Compactification	Concept	General topology
Large deviations theory	Concept	Probability theory and stochastic processes