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: 
discretegeometry× 344
Finite or discrete collections of geometric objects. Packings, tilings, polyhedra, polytopes, intersection, arrangements, rigidity.

smoothmanifolds× 342
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…

sequencesandseries× 341 
abelianvarieties× 331
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. …

vectorbundles× 330
A continuously varying family of vector spaces of the same dimension over a topological space. If the vector spaces are onedimensional, the term line bundle is used and has the associated tag linebu…

computerscience× 322
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× 322
a method first used to prove the continuum hypothesis is independent of the classical axioms of set theory

sheaftheory× 320 
inequalities× 320 
convexpolytopes× 315
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…

openproblem× 313
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…

examples× 307 
ergodictheory× 305
Dynamical systems on measure spaces, invariant measures, ergodic averages, mixing properties.

hyperbolicgeometry× 304  simplicialstuff× 299 
sp.spectraltheory× 297
Schrodinger operators, operators on manifolds, general differential operators, numerical studies, integral operators, discrete models, resonances, nonselfadjoint operators, random operators/matrices…

lattices× 293
used in number theory. (Not to be confused with lattice theory or lattices as used in physics!)

galoistheory× 289  integration× 277  groupcohomology× 272 
terminology× 271 
specialfunctions× 269
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.

convexity× 266  riemannsurfaces× 259 
convexgeometry× 252  diophantineequations× 247  deformationtheory× 243 
it.informationtheory× 243
Covers theoretical and experimental aspects of information theory and coding.

automorphicforms× 241  modelcategories× 239  etalecohomology× 235 
geometricgrouptheory× 234
Large scale properties of groups; growth functions; Dehn functions; small cancellation properties; hyperbolicity and CAT(0); actions and representations; combinatorial group theory; presentations

stacks× 230  galoisrepresentations× 226 
bigpicture× 224
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× 224 