# Tags

A tag is a keyword or label that categorizes your question with other, similar questions. Using the right tags makes it easier for others to find and answer your question.

 Type to find tags:
 mean-square-error× 83 for questions about mean-square-error. In statistics, the mean squared error (MSE) of an estimator measures the average of the squares of the errors or deviations, that is, the difference … holomorphic-functions× 82 mobius-function× 82 Questions on the Möbius function μ(n), an arithmetic function used in number theory. formal-power-series× 81 confidence-interval× 81 gradient-flows× 80 An ordinary differential equation that generalizes the notion of "path of steepest descent." For questions on "gradients" of a function, use (multivariable-calculus) instead. monomial-ideals× 80 publishing× 80 For questions about publishing mathematical content. rigid-transformation× 80 mappings from one reference frame to another reference frame in the Euclidean space $\mathbb R^n$. They comprise translation, rotation (and sometimes reflection). More for… linear-groups× 79 a group $G$ whose elements are invertible $n \times n$ matrices over a field $F$. quadratic-variation× 78 Questions on quadratic variations of stochastic processes. (Not to be confused with functions of bounded variation.) quantum-computation× 77 Quantum Computation deals with considering computation as fundamentally physical, as well as replacing the classical binary digit (bit) with the quantum binary digit (qubit). While the classical bit i… profinite-groups× 77 For questions regarding profinite groups and their properties. perfect-powers× 77 a positive integer that can be expressed as an integer power of another positive integer. This tag should only be used when having in mind an arbitrary perfect power (as opposed t… linear-approximation× 77 For questions about linear approximations, $f(x) \approx f(a)+f'(a)(x-a)$ for $x$ around $a$. fuzzy-logic× 77 a form of many-valued logic that deals with approximate, rather than fixed and exact reasoning. (Def: http://en.m.wikipedia.org/wiki/Fuzzy_logic) cohen-macaulay× 77 called Cohen-Macaulay if its depth is equal to its dimension. More generally, a commutative ring is called Cohen-Macaulay if is Noetherian and all of its localizations at prime ideals are Co… young-tableaux× 77 blowup× 76 A technique in geometry (especially algebraic and differential, and by extension to study of pseudo-differential operators) for resolution of singularities. Not to be confused with the formation of si… function-fields× 76 deformation-theory× 75 The study of how mathematical objects (complex manifolds, associative algebras, Lie algebras) can be deformed into similar mathematical objects, at least infinitesimally. multivalued-functions× 75 In Mathematics, set theory, a Multivalued function is defined as a left-total relation (that is, every input is associated with at least one output) in which at least one input is associated with mult… random-functions× 74 power-towers× 73 For questions pertaining to power towers: expressions like a^(b^(c^d))), which result from iterated exponentiation. The "hyperoperation" tag may be appropriate, too. noneuclidean-geometry× 73 .............................. lagrange-interpolation× 73 A method of generating a polynomial that crosses through a set of data. The degree of this polynomial is equal to the size of the data. metric-geometry× 73 The study of geometry of manifolds without appealing to differential calculus. It includes studies of length spaces, Alexandrov spaces, and CAT(k) spaces. The techniques are often applicable to Rieman… goldbachs-conjecture× 73 For questions about Goldbach's conjecture: every even integer greater than two is the sum of two primes. cauchy-principal-value× 73 Computation of Cauchy principal values of integrals. May be tied in with contour integration, but should be separate from definite-integrals. chemistry× 73 Questions related to mathematical chemistry which include application of mathematics to problems in chemistry and the development of mathematical methods suitable for such applications and for the for… gauge-theory× 72 Connections on principal bundles, gauge groups, Yang-Mills connections, (anti-)self-dual connections, stability of vector bundles, Donaldson invariants, the Seiberg-Witten equations and invariants, th… groupoids× 72 A groupoid (in the sense of category theory) is a small category in which every morphism is an isomorphism. Groupoids arise throughout mathematics, e.g. in guise of fundamental groupoids in the theory… provability× 72 rngs× 72 an associative ring without necessarily having a multiplicative identity (rng = ring - $i$dentity). lie-derivative× 71 The Lie derivative gives a way to define the derivative of a tensor field in the direction of a vector field. geometric-inequalities× 71 a tag for geometric problems involving inequalities.