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: 
bigpicture× 229
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 subfields of mat…

schemes× 229
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…

largecardinals× 227  topologicalgroups× 224 
singularitytheory× 223  asymptotics× 221  finitefields× 220 
fields× 218
Fields as algebraic objects. For vector and tensor fields, use eg. [dg.differentialgeometry]. For physical fields, use eg. [mp.mathematicalphysics] or [quantumfieldtheory].

3manifolds× 216  ordertheory× 214  abstractalgebra× 210  quadraticforms× 209 
quantumgroups× 209
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…

randommatrices× 208
Statistics of spectral properties of matrixvalued random variables.

noncommutativegeometry× 207
Noncommutative geometry in the sense of Connes and beyond: noncommutative algebras viewed as functions on a noncommutative space.

mathematicseducation× 207
For questions in Mathematics Education as a scientific discipline. For more handson questions on teaching Mathematics, please use the tag teaching. There is also a Stack Exchange community http://mat…

noncommutativealgebra× 205 
intuition× 203
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…

sobolevspaces× 203 
derivedcategory× 203
For questions about the derived categories of various abelian categories and questions regarding the derived category construction itself.

topostheory× 203  modules× 201  linearprogramming× 201  vonneumannalgebras× 200 
hopfalgebras× 199
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…

operatortheory× 197
Spectrum, resolvent, numerical range, functional calculus, operator semigroups. Special classes of operators: compact, Fredholm, dissipative, differential, integral, pseudodifferential, etc.

combinatorialgeometry× 196 
ellipticpde× 194
Questions about partial differential equations of elliptic type. Often used in combination with the toplevel tag ap.analysisofpdes.

algebraicktheory× 191 
additivecombinatorics× 190
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,…

matrixanalysis× 183
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…

markovchains× 182 
commutativerings× 181  motives× 180  projectivegeometry× 180  characteristicp× 179 