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: 
sequencesandseries× 328 
smoothmanifolds× 327
Smooth manifolds and smooth functions between them. For manifolds with additional structure, see more specific tags, such as [riemanniangeometry]. For more topological aspects, see [differentialtopo…

discretegeometry× 320
Finite or discrete collections of geometric objects. Packings, tilings, polyhedra, polytopes, intersection, arrangements, rigidity.

abelianvarieties× 319
projective algebraic varieties endowed with an Abelian group structure. Over the complex numbers, they can be described as quotients of a vector space by a lattice of full rank. …

sheaftheory× 318  vectorbundles× 316 
computerscience× 312
For question borderline with, or having application to, computer science. Consider also posting http://cs.stackexchange.com/ or http://cstheory.stackexchange.com/ instead of here, if appropriate.

forcing× 309
a method first used to prove the continuum hypothesis is independent of the classical axioms of set theory

openproblem× 308
equivalent to a known open problem, then the openproblem tag is added. After that, the question essentially becomes, "What is known about this problem? What are some…

convexpolytopes× 304
the convex hulls of a finite set of points in Euclidean spaces. They have rich combinatorial, arithmetic, and metrical theory, and are related to toric varieties and to linear pr…

inequalities× 303  examples× 300 
hyperbolicgeometry× 296 
ergodictheory× 294
Dynamical systems on measure spaces, invariant measures, ergodic averages, mixing properties.

simplicialstuff× 292 
lattices× 288
used in number theory. (Not to be confused with lattice theory or lattices as used in physics!)

sp.spectraltheory× 284
Schrodinger operators, operators on manifolds, general differential operators, numerical studies, integral operators, discrete models, resonances, nonselfadjoint operators, random operators/matrices…

galoistheory× 284  integration× 265  groupcohomology× 262 
convexity× 258 
specialfunctions× 258
Many special functions appear as solutions of differential equations or integrals of elementary functions. Most special functions have relationships with representation theory of Lie groups.

terminology× 254  riemannsurfaces× 253 
convexgeometry× 244  deformationtheory× 239 
it.informationtheory× 239
Covers theoretical and experimental aspects of information theory and coding.

diophantineequations× 237 
etalecohomology× 231  automorphicforms× 231  modelcategories× 229  stacks× 225 
galoisrepresentations× 223 
geometricgrouptheory× 221
Large scale properties of groups; growth functions; Dehn functions; small cancellation properties; hyperbolicity and CAT(0); actions and representations; combinatorial group theory; presentations

bigpicture× 221
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…

stochasticcalculus× 221 