# 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:
 laplace-transform× 903 a widely used integral transform, similar to the Fourier transform. vectors× 889 for questions involving vectors, quantities that have magnitude and direction. model-theory× 885 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… abelian-groups× 885 Should be used with the (group-theory) tag. A group $(G,*)$ is said to be abelian if $a*b=b*a$ for all $a,b\in G.$ normed-spaces× 882 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. analytic-number-theory× 868 Questions on the use of the methods of real/complex analysis in the study of number theory. conic-sections× 834 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× 828 "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… functional-equations× 822 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… tensor-products× 816 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… numerical-linear-algebra× 809 Questions on the various algorithms used in linear algebra computations (matrix computations). game-theory× 807 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… expectation× 804 For questions about the expectation of a random variable: computations, upper/below bounds, etc... lp-spaces× 803 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.… inner-product-space× 800 a vector space equipped with an inner product. The inner product is a generalisation of the "dot" product often used in vector calculus. boolean-algebra× 788 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 … lebesgue-measure× 777 For questions about the Lebesgue measure, a measure defined on the Borel or Lebesgue subsets of the real line or $\mathbb R^d$ for some integer $d$. Use it with (tag: measure-theory) tag and (if neces… combinations× 774 subsets of a given size of a given finite set. All questions for this tag have to directly involve combinations; if instead the question is about binomial coefficients, use that tag. homotopy-theory× 764 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… factoring× 762 For questions about finding factors of e.g. integers or polynomials factorial× 751 Questions on the factorial function, $n!=n\times(n-1)\times\cdots\times1$. Consider using the tag (gamma-function) if dealing with noninteger arguments. contour-integration× 751 Questions on the evaluation of integrals along a locus in the complex plane. coordinate-systems× 751 Questions on coordinate systems, a geometric method where a point in n-dimensions is assigned a corresponding n-tuple of numbers. big-list× 745 Questions asking for a "big list" of examples, illustrations, etc. Please do not ask too many of these. Please do not use this as the only tag for a question. 3d× 745 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… brownian-motion× 721 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… computability× 714 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 … closed-form× 708 any representation of a mathematical expression in terms of "known" functions, "known" usually being replaced with "elementary". distribution-theory× 695 for questions about Schwartz distributions, also known as Generalised Functions. For questions about "probability distributions", use (probability-distributions). For questions about dist… solution-verification× 685 For posts looking for feedback or verification of a proposed solution. regression× 685 Questions on (linear or nonlinear) regression, the fitting of functions that best approximate empirical data. axiom-of-choice× 678 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… operator-algebras× 674 primarily C*-algebras and von Neumann algebras, and associated topics. It also includes more general algebras of operators on Hilbert space, and may include algebr… extension-field× 667 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… elliptic-curves× 653 For questions regarding elliptic curves. Questions on ellipses should be tagged [conic-sections] instead. rotations× 650 for questions about *rotations*: a type of rigid motion in a space.