# 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:
 homology-cohomology× 1099 if your question involves some type of (co)homology, including (but not limited to) simplicial, singular or group (co)homology. Consider the tag (homological-algebra) for more abstract as… cardinals× 1091 for questions about cardinals and related topics such as cardinal arithmetics, regular cardinals and cofinality. Do not confuse with [large-cardinals] which is a technical concept about st… normed-spaces× 1086 A vector space $E$, generally over the field $\mathbb R$ or $\mathbb C$ with a map $\lVert \cdot\rVert\colon E\to \mathbb R_+$ satisfying some conditions. expectation× 1077 For questions about the expectation of a random variable: computations, upper/lower bounds, etc. computational-complexity× 1072 Computational complexity, a part of theoretical computer science that deals with understanding how efficiently a problem can be solved. model-theory× 1066 the study of (classes of) mathematical structures (e.g. groups, fields, graphs, universes of set theory) using tools from mathematical logic. Objects of study in model theory are mode… contour-integration× 1030 Questions on the evaluation of integrals along a locus in the complex plane. solution-verification× 1016 For posts looking for feedback or verification of a proposed solution. abelian-groups× 1001 Should be used with the (group-theory) tag. A group $(G,*)$ is said to be abelian if $a*b=b*a$ for all $a,b\in G.$ conic-sections× 999 Questions on conic sections and their properties; the curves formed by the intersection of a plane and a cone. Circles, ellipses, hyperbolas, and parabolas are examples of conic sections. mathematical-physics× 997 "Mathematical physics consists of the application of mathematics to problems in physics and the development of mathematical methods suitable for such applications and for the formulation of physical t… lp-spaces× 997 For questions about $L^p$ spaces, that is, given a measure space $(X,\mathcal F,\mu)$, the vector space of equivalence class of measurable functions with $p$-th power of the absolute value integrable.… analytic-number-theory× 987 Questions on the use of the methods of real/complex analysis in the study of number theory. inner-product-space× 986 a vector space equipped with an inner product. The inner product is a generalisation of the "dot" product often used in vector calculus. tensor-products× 985 Tensor products allow us to build "linear" objects from "multilinear" ones. It can refer to: basic ones from linear algebra/module theory, or more sophisticated versions from differential/algebraic ge… functional-equations× 978 used for problems where the goal is to find all functions satisfying the given equation (and maybe some other conditions). So in this case, solving the equation means… factoring× 958 For questions about finding factors of e.g. integers or polynomials homotopy-theory× 950 homotopic, if one of them can by continuously deformed to another. This gives rise to an equivalence relation. A group called homotopy group can be obtained from the equivalence clas… numerical-linear-algebra× 942 Questions on the various algorithms used in linear algebra computations (matrix computations). game-theory× 938 The study of competitive and non-competitive games, equilibrium concepts such as Nash equilibrium, and related subjects. Combinatorial games such as Nim are under (combinatorial-game-theory), and algo… extension-field× 928 for questions about extension fields in abstract algebra. An extension field of a field K is just a field containing K as subfield, but interesting questions arise with them. Use this… factorial× 924 Questions on the factorial function, $n!=n\times(n-1)\times\cdots\times1$. Consider using the tag (gamma-function) if dealing with noninteger arguments. brownian-motion× 919 Questions related to Brownian motion, a continuous stochastic process denoted by $W_t$, $t\geq 0$, with independent increments, such that $W(t)-W(s)$ is normally distributed, with $0$ mean and varianc… boolean-algebra× 908 structures which behave similar to a power set with complement, intersection and union. Questions regarding Boolean algebras as structures, or regarding functions defined from/to … coordinate-systems× 906 Questions on coordinate systems, a geometric method where a point in n-dimensions is assigned a corresponding n-tuple of numbers. conditional-probability× 900 the probability that an event occurs given something else has already occurred. closed-form× 872 any representation of a mathematical expression in terms of "known" functions, "known" usually being replaced with "elementary". 3d× 864 is for things related to 3-dimensions. For geometry of 3-dimensional solids, please use instead (solid-geometry). For geometry that is not on a plane, but otherwise agnostic of dimensions… big-list× 826 Questions asking for a "big list" of examples, illustrations, etc. Ask only when the topic is compelling, and please do not use this as the only tag for a question. computability× 826 Questions about Turing computability and recursion theory, including the halting problem and other unsolvable problems. Questions about the resources required to solving particular problems should be … distribution-theory× 800 for questions about Schwartz distributions, also known as Generalised Functions. For questions about "probability distributions", use (probability-distributions). For questions about dist… predicate-logic× 781 Questions concerning predicate calculus, i.e. the logic of quantifiers. algebraic-curves× 779 an algebraic variety of dimension one. An affine algebraic curve can be described as the zero-locus of $n-1$ independent polynomials of $n$ variables in affine $n$-space over a f… uniform-convergence× 773 For questions about uniform convergence of a sequence or a series of functions on a set. Also used with the tag [convergence]. calculus-of-variations× 771 Questions on the calculus of variations, which deals with the optimization of functionals mostly defined on an infinite dimensional spaces. axiom-of-choice× 770 a common set-theoretic axiom with many equivalents and consequences. This tag is for questions on where we use it in certain proofs, and how things would work without the assump…