# 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:
 stable-homotopy× 157 manifolds× 155 math-philosophy× 154 algebraic-surfaces× 152 elliptic-pde× 152 Questions about partial differential equations of elliptic type. Often used in combination with the top-level tag ap.analysis-of-pdes. matrix-analysis× 150 The study of real and complex matrices and their algebraic and analytical properties, including: eigenvalues and eigenvectors, positive definite matrices, matrix inequalities, invariant subspaces, per… operator-theory× 150 Spectrum, resolvent, numerical range, functional calculus, operator semigroups. Special classes of operators: compact, Fredholm, dissipative, differential, integral, pseudodifferential, etc. approximation-theory× 148 birational-geometry× 143 monoidal-categories× 140 langlands-conjectures× 138 Higher reciprocity laws random-walk× 138 computational-geometry× 138 Using computers to solve geometric problems. Questions with this tag should typically have at least one other tag indicating what sort of geometry is involved, such as ag.algebraic-geometry or mg.metr… hilbert-spaces× 138 textbook-recommendation× 138 Questions asking for recommendations of textbooks on some subject. It can be helpful to indicate whether the request is for self-study, for use in a course one teaches, for use accompanying a course o… computer-algebra× 137 Using computers to solve algebraic problems. Questions with this tag should typically include at least one other tag indicating what sort of algebraic problem is involved, such as ac.commutative-algeb… proof-theory× 137 For question in Proof Theory, where "proofs" themselves are the object of mathematical investigation. It is not to be used to request a proof of some result. semigroups× 136 books× 132 Questions in which books play a key-role, such as questions on antique books, e-books, difference between various editions of a book, etc. For questions asking for recommendations of books on some sub… riemann-zeta-function× 131 the function of one complex variable $s$ defined by the series $\zeta(s) = \sum_{n \geq 1} \frac{1}{n^s}$ when $\operatorname{Re}(s)>1$. It admits a meromorphic continuati… homology× 129 universal-algebra× 129 zeta-functions× 129 l-functions× 127 Questions about generalizations of the Riemann Zeta function of arithmetic interest whose definition relies on meromorphic continuation of special kinds of Dirichlet series, such as Dirichlet L-functi… gm.general-mathematics× 127 euclidean-geometry× 126 calculus-of-variations× 126 linear-programming× 122 career× 121 intersection-theory× 120 class-field-theory× 118 group-actions× 117 permutations× 116 Questions related to permutations, bijections from a finite (or sometimes infinite) set to itself. convex-optimization× 114 graph-colorings× 111 differential-operators× 111 Elliptic, parabolic and hyperbolic operators. Laplace, Laplace-Beltrami, Schrödinger, Dirac. Exterior derivative and Lie derivative operators.