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: 
computabilitytheory× 373
computable sets and functions, Turing degrees, c.e. degrees, models of computability, primitive recursion, oracle computation, models of computability, decision problems, undecidability, Turing jump, …

sequencesandseries× 366 
vectorbundles× 366
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…

inequalities× 355 
forcing× 353
a method first used to prove the continuum hypothesis is independent of the classical axioms of set theory

convexpolytopes× 350
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…

abelianvarieties× 342
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. …

computerscience× 334
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.

ergodictheory× 331
Dynamical systems on measure spaces, invariant measures, ergodic averages, mixing properties.

sheaftheory× 331  simplicialstuff× 327 
sp.spectraltheory× 325
Schrodinger operators, operators on manifolds, general differential operators, numerical studies, integral operators, discrete models, resonances, nonselfadjoint operators, random operators/matrices…

hyperbolicgeometry× 323 
openproblem× 319
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× 315  integration× 313 
lattices× 311
used in number theory. (Not to be confused with lattice theory or lattices as used in physics!)

galoistheory× 307  groupcohomology× 301  terminology× 301 
specialfunctions× 287
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× 282 
geometricgrouptheory× 275
Large scale properties of groups; growth functions; Dehn functions; small cancellation properties; hyperbolicity and CAT(0); actions and representations; combinatorial group theory; presentations

convexgeometry× 271 
riemannsurfaces× 271  diophantineequations× 266  modelcategories× 260 
it.informationtheory× 258
Covers theoretical and experimental aspects of information theory and coding.

deformationtheory× 257  automorphicforms× 252 
cstaralgebras× 251
a complex Banach algebra together with an isometric antilinear involution satisfying (a b)* = b* a* and the C*identity ‖a* a‖ = ‖a‖². Related tags: [tag:banachalgebras], [tag:vonne…

stacks× 250 
stochasticcalculus× 249
Stochastic calculus provides a consistent theory of integration for stochastic processes and is used to model random systems. Its applications range from statistical physics to quantitative finance.

etalecohomology× 243  largecardinals× 240  axiomofchoice× 239 