# 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:
 big-picture× 237 Questions designed to get an overview of a specific subject or body of results or to understand the relations among similar definitions, techniques or concepts appearing in different sub-fields of mat… galois-representations× 236 schemes× 235 the geometrical study of solutions of algebraic systems of equations, not only over the real/complex numbers, but also over integer numbers (and more generally o… order-theory× 232 asymptotics× 232 finite-fields× 230 topological-groups× 230 singularity-theory× 227 sobolev-spaces× 227 fields× 225 Fields as algebraic objects. For vector and tensor fields, use eg. [dg.differential-geometry]. For physical fields, use eg. [mp.mathematical-physics] or [quantum-field-theory]. 3-manifolds× 222 random-matrices× 222 Statistics of spectral properties of matrix-valued random variables. abstract-algebra× 217 derived-category× 216 For questions about the derived categories of various abelian categories and questions regarding the derived category construction itself. operator-theory× 216 Spectrum, resolvent, numerical range, functional calculus, operator semigroups. Special classes of operators: compact, Fredholm, dissipative, differential, integral, pseudodifferential, etc. quadratic-forms× 214 modules× 214 noncommutative-geometry× 214 Noncommutative geometry in the sense of Connes and beyond: noncommutative algebras viewed as functions on a noncommutative space. elliptic-pde× 214 Questions about partial differential equations of elliptic type. Often used in combination with the top-level tag ap.analysis-of-pdes. mathematics-education× 213 For questions in Mathematics Education as a scientific discipline. For more hands-on questions on teaching Mathematics, please use the tag teaching. There is also a Stack Exchange community http://mat… noncommutative-algebra× 212 quantum-groups× 212 Questions about algebraic structures known as quantum groups, and their categories of representations. Quasitriangular Hopf algebras and their Drinfel'd twists, triangular Hopf algebras, $C^\star$ qua… topos-theory× 209 von-neumann-algebras× 207 intuition× 207 Questions asking for the intuition behind some definition, conjecture, proof etc. In other words, questions designed to improve or to acquire understanding on a conceptual or intuitive level, as oppos… linear-programming× 204 hopf-algebras× 202 a vector space $H$ over a field $k$ endowed with an associative product $\times:H\otimes_k H\to H$ and a coassociative coproduct $\Delta:H\to H\otimes_k H$ which is a morphism of alg… additive-combinatorics× 197 Questions on the subject additive combinatorics, also known as arithmetic combinatorics, such as questions on: additive bases, sum sets, inverse sum set theorems, sets with small doubling, Sidon sets,… commutative-rings× 197 combinatorial-geometry× 196 algebraic-k-theory× 196 descriptive-set-theory× 196 the study of definable subsets of Polish spaces, where definable is taken to mean from the Borel or projective hierarchies. Other topics include infinite games and determinac… matrix-analysis× 196 The study of the properties of real and complex matrices that are more close to analysis and operator theory. For instance: the properties of positive definite matrices, matrix inequalities, perturbat… projective-geometry× 191 markov-chains× 186 motives× 183