# 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.

× 2197
a quantity that expresses the extent of a two-dimensional or three-dimensional surface or shape.
× 2189
structures which behave similar to a power set with complement, intersection and union. Use this tag for questions about Boolean algebras as structures, or about functions defined…
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For every question related to the concept of conditional expectation of a random variable with respect to a $\sigma$-algebra. It should be used with the tag (probability-theory) or (probability), and …
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for questions about recommendation of books for some particular area, topic, problem. Use this tag together with (reference-request) tag.
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about doing calculus, especially derivative and infinite series over spaces of vectors and matrices.
× 2127
for questions about distributions (or generalized functions). For questions about "probability distributions", use (probability-distributions). For questions about distributions as sub-bu…
× 2114
Questions on polar coordinates, a coordinate system where points are represented by their distance from the origin ($r$) and the angle the line joining the point and the origin makes with the positive…
× 2087
for questions concerning history of mathematics, historical primacies of results, and evolution of terminology, symbols, and notations. Consider if History of Science and Mathematics Stac…
× 2068
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…
× 2065
For questions about differential forms, a class of objects in differential geometry and multivariable calculus that can be integrated.
× 2061
Often called prime polynomials. Polynomials that have no polynomial divisors.
× 2055
For simultaneously reflexive, symmetric and transitive relations. Use it with the tag (relations).
× 2030
For questions about tensor, tensor computation and specific tensors (e.g.curvature tensor, stress tensor).
× 2027
For questions related to volume, the amount of space that a substance or object occupies.
× 2021
a two-dimensional submanifold of three-dimensional Euclidean space.
× 2010
For questions about or involving the absolute value function.
× 2006
for questions about *rotations*: a type of rigid motion in a space.
× 1991
the study of complex manifolds and complex algebraic varieties. It is a part of both differential geometry and algebraic geometry. For elementary questions about geometry in the c…
× 1987
If you already have a proof for some result but want to ask for a different proof (using different methods).
× 1946
for question on connected spaces and various related notions (connected components, locally connected spaces, pathwise/arcwise connected spaces, simply connected spaces, totally disconnec…
× 1922
A non-linear optimization problem includes an objective function (to be minimized or maximized) and some number of equality and/or inequality constraints where the objective or some of the constraints…
× 1909
For question about discrete or continuous (super/sub)martingales. Often used with [probability-theory] tag.
× 1883
The evaluation of limits without the usage of L'Hôpital's rule.
× 1875
Questions on (linear or nonlinear) regression, the fitting of functions that best approximate empirical data.
× 1845
Optimization of functionals mostly defined on infinite-dimensional spaces.
× 1844
Questions on the (continuous or discrete) convolution of two functions. It can also be used for questions about convolution of distributions (in the Schwartz's sense) or measures.
× 1836
the study of generalized notions of eigenvalues and eigenvectors for linear operators in Banach spaces.
× 1832
For questions regarding elliptic curves. Questions on ellipses should be tagged [conic-sections] instead.
× 1810
Questions on the gamma function $\Gamma(z)$ of Euler extending the usual factorial $n!$ for arbitrary argument, and related functions.
× 1796
For questions about parametric equations, their application, equivalence to other equation types and definition.
× 1793
For questions about or involving curves.
× 1788
For questions about congruences in modular arithmetic, concerning for example the chinese remainder theorem, Fermat's little theorem or Euler's totient theorem.
× 1772
Questions having to do with financial mathematics. This is not a tag about financing, which is not within the scope of mathematics defined by the help center: http://math.stackexchange.com/help/on-top…
× 1771
A Sheaf $\mathcal F$ on a topological space $X$ captures local data $\mathcal F(U)$ given on open sets $U\subseteq X$ and how such data can be restricted to smaller open sets or glued together. In typ…
× 1763
the generalisation of Fourier analysis. Use this tag for analysis on locally compact groups (e.g. Pontryagin duality), eigenvalues of the Laplacian on compact manifolds or graphs,…
× 1762
Questions on the evaluation of residues, on the evaluation of integrals using the method of residues or in the method's theory.