6,052 articles
Superstable theories
In model theory, a superstable theory is a stable theory in which every type does not fork over a finite subset of its domain, a class introduced by Saharon Shelah.
Support (mathematics)
In mathematics, the support of a function, measure, or distribution is the closed set on which it is nonzero or concentrated; compact support is central to distribution theory.
Surface (topology)
A surface in topology is a two-dimensional manifold, a space that looks locally like a plane, with examples including the sphere, the torus, and the Klein bottle.
Surface area
Surface area is the measure of the total area of the surface of a three-dimensional object, expressed in squared units; a sphere's is 4πr², proved by Archimedes.
Surface group
A surface group is a group isomorphic to the fundamental group of a closed surface, a connected compact surface without boundary, with explicit one-relator presentations for orientable and non-orientable cases.
Surface integral
A surface integral is an integral taken over a two-dimensional surface in space, of a scalar function or a vector field, measuring how much field passes through, called flux.
Surjective function
A surjective function, also called an onto function or surjection, is a function in which every element of the codomain is the output of at least one domain element.
Surreal number
The surreal numbers, also called Conway numbers, form an ordered number system defined by John Conway around 1970 from Go endgames, containing the reals, all ordinals, and infinitesimals.
Surrogate data testing
Surrogate data testing is a Monte Carlo hypothesis test for time series, comparing a statistic against randomized copies that preserve linear properties like the Fourier spectrum.
Survey methodology
Survey methodology is the field of statistics and social science that studies how to collect data from samples of people, covering sample design, questionnaires, and nonsampling errors.
Survey of Consumer Finances
The Survey of Consumer Finances is a triennial survey of US families sponsored by the Federal Reserve Board, the primary source of household wealth data.
Survey of Income and Program Participation
The Survey of Income and Program Participation (SIPP) is a longitudinal household survey run by the U.S. Census Bureau since 1983, tracking income, employment, and government program participation.
Survey Research Methods
Survey research methods are the procedures for questioning a representative sample of a population and the statistical techniques for designing studies, collecting data, and measuring error.
Survey weighting
Survey weighting assigns numerical weights to survey records so sample estimates describe the target population rather than the sample itself, compensating for unequal selection probabilities, nonresponse, and coverage problems.
Survival analysis
Survival analysis, also called time to event analysis, is a branch of statistics for modeling time until an event, such as death or equipment failure, with censored data.
Suslin cardinal
A Suslin cardinal is an ordinal κ for which some set of reals is κ-Suslin but no smaller ordinal suffices; ℵ₁ is the classical example in descriptive set theory.
Suslin operation
The Suslin operation, also called operation A, is a set-theoretic operation that takes families indexed by finite sequences of naturals; applied to closed sets, it yields the analytic sets.
Suzuki sporadic group
The Suzuki sporadic group (Suz) is one of the 26 sporadic simple groups, a finite simple group constructed by the Japanese mathematician Michio Suzuki in 1968.
Sweep algorithm
The sweep algorithm is a cluster-first, route-second heuristic for the capacitated vehicle routing problem, grouping customers by polar-coordinate angle around the depot; Gillett and Miller popularized it in 1974.
Switching regression
A switching regression is a statistical model in which the relationship between variables switches among a few regimes, each with its own coefficients and error variance.
Sylow p-subgroup
A Sylow p-subgroup of a finite group G is a subgroup whose order is the largest power of a prime p dividing the order of G, named for Ludwig Sylow.
Sylow theorems
The Sylow theorems (Sylow's first theorem) are three results of finite group theory proved by Ludwig Sylow in 1872, guaranteeing Sylow p-subgroups for every prime power dividing a group's order.
Sylvester equation
The Sylvester equation is the matrix equation AX + XB = C for an unknown matrix X, named after James Joseph Sylvester, who studied it in 1884.
Sylvester matrix
The Sylvester matrix of two univariate polynomials is the square matrix of their coefficients, of size equal to the sum of the two degrees, whose determinant is the resultant.
Sylvester's criterion
Sylvester's criterion is a test in linear algebra that determines whether a symmetric or Hermitian matrix is positive definite by checking that all its leading principal minors are positive.
Symbolic dynamics
Symbolic dynamics is a branch of dynamical systems theory that studies infinite sequences of symbols over a finite alphabet under the shift map, used to code continuous systems.
Symbolic integration
Symbolic integration computes an exact closed-form antiderivative of a mathematical expression rather than a numerical approximation, a core capability of computer algebra systems built on the Risch algorithm.
Symbolic method (combinatorics)
The symbolic method is a technique in enumerative combinatorics for translating formal definitions of combinatorial objects into generating functions, systematized by Philippe Flajolet and Robert Sedgewick.
Symbolic regression
Symbolic regression (SR) is a machine learning task that searches for both the form and parameters of a mathematical expression fitting data, returning explicit equations.
Symmetric algebra
The symmetric algebra S(M) of a module M is the commutative algebra obtained by quotienting its tensor algebra to make elements commute; for a free module it is a polynomial ring.