Tags
A tag is a keyword or label that categorizes your question with other, similar questions.
For questions on suprema and infima. Use together with a subject area tag, such as (real-analysis) or (order-theory).
2933 questions
For questions regarding $\varepsilon$-$\delta$ definitions of limits, continuity of functions and $\varepsilon-N$ definition of limit of sequences.
2881 questions
For questions on vector bundles, a topological construction that makes precise the idea of a family of vector spaces parameterized by another space $X$.
2866 questions
Recursion is the process of repeating items in a self-similar way. A recursive definition (or inductive definition) in mathematical logic and computer science is used to define an object in terms of itself.
A recursive definition of a function defines values of a function for some inputs in terms of the values of the same function on other inputs. Please use the tag 'computability' instead for questions about "recursive functions" in computability theory
2829 questions
In vector calculus, a vector field is an assignment of a vector to each point in a subset of space. A vector field in the plane, for instance, can be visualized as a collection of arrows with a given magnitude and direction each attached to a point in the plane. Vector fields are often used to model, for example, the speed and direction of a moving fluid throughout space.
2822 questions
This tag is for the questions on Lagrange multipliers. The method of Lagrange multipliers (named after Joseph Louis Lagrange) provides a strategy for finding the local maxima and minima of a function subject to equality constraints.
2808 questions
A C*-algebra is a complex Banach algebra together with an isometric antilinear involution satisfying $(ab)^*=b^*a^*$ and the C*-identity $\Vert a^*a\Vert=\Vert a\Vert^2$. Related tags: (banach-algebras), (von-neumann-algebras), (operator-algebras), (spectral-theory).
2807 questions
Harmonic analysis is 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, and the abstract study of Fourier transform on Euclidean spaces (singular integrals, Littlewood-Paley theory, etc). Use the (wavelets) tag for questions on wavelets, and the (fourier-analysis) for more elementary topics in Fourier theory.
2797 questions
The concept of scheme mimics the concept of manifold obtained by gluing pieces isomorphic to open balls, but with different "basic" gluing pieces. Properly, a scheme is a locally ringed space locally isomorphic (in the category of locally ringed spaces) to an affine scheme, the spectrum of a commutative ring with unit.
2781 questions
A symmetric group is a group consisting of all permutations of given finite set, with composition of permutations as the binary operation. Should be used with the (group-theory) tag.
2772 questions
Questions on the evaluation of residues, on the evaluation of integrals using the method of residues or in the method's theory.
2742 questions
Use this tag for questions concerning history of mathematics, historical primacies of results, and evolution of terminology, symbols, and notations. Consider if History of Science and Mathematics Stack Exchange is a better place to ask your question.
2736 questions
This tag is for questions on (linear or nonlinear) regression, which is a way of describing how one variable, the outcome, is numerically related to predictor variables. The dependent variable is also referred to as $~Y~$, dependent or response and is plotted on the vertical axis (ordinate) of a graph.
2700 questions
For questions related to gcd (greatest common divisor, also known as the hcf, the highest common factor), lcm (least common multiple), and related concepts from integer and ring theory.
2686 questions
Questions about matrix decompositions, such as the LU, Cholesky, SVD (Singular value decomposition) and eigenvalue-eigenvector decomposition.
2679 questions
This tag can be used to refer to the orthogonality of a set of vectors, a matrix or a linear transformation.
2666 questions
Questions on the famed $\zeta(s)$ function of Riemann, and its properties.
2642 questions
Questions related to the various aspects of financial mathematics. Topics include option pricing, arbitrage theory, market completeness and stochastic analysis.
2637 questions
The Riemann integral, created by Bernhard Riemann, was the first rigorous definition of the integral of a function on an interval. For many functions and practical applications, the Riemann integral can be evaluated by the fundamental theorem of calculus or approximated by numerical integration.
2619 questions
For questions about the structure, definition, and basic properties of the set of integers, or positive and negative whole numbers, commonly denoted $\mathbb{Z}$. Do not use this tag just because your question involves integers. Consider using (elementary-number-theory) or (number-theory) instead of or in addition to this tag.
2606 questions
For questions about weak convergence, which can concern sequences in normed/ topological vectors spaces, or sequences of measures.
Please use other tags like (tag: functional-analysis) or (tag: probability-theory).
2594 questions
A stochastic process satisfying the Markov property: the distribution of the future states given the value of the current state does not depend on the past states. Use this tag for general state space processes (both discrete and continuous times); use (markov-chains) for countable state space processes.
2574 questions
For questions about parametric equations, their application, equivalence to other equation types and definition.
2565 questions
Projective geometry is closely related to perspective geometry. These types of geometry originated with artists around the 14th century.
2534 questions
For questions regarding the variance of a random variable in probability, as well as the variance of a list or data in statistics.
2532 questions
For questions concerning normal subgroups of groups. Consider using with the (group-theory) and/or the (abstract-algebra) tags too.
2517 questions
An algebraic curve is 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 field. Examples include conic sections, compact Riemann surfaces and elliptic curves. Singularities of curves are extensively studied as a basic case in singularity theory. Via algebraic function fields and modular curves they have links to number theory.
2500 questions
For questions about matrix diagonalization. Diagonalization is the process of finding a corresponding diagonal matrix for a diagonalizable matrix or linear map. This tag is NOT for diagonalization arguments common to logic and set theory.
2484 questions
Control theory is an interdisciplinary branch of engineering and mathematics that deals with the behavior of dynamical systems with inputs. The desired trajectory of the output of a system is called the reference. When one or more output variables of a system need to follow a certain reference over time, a controller should manipulate the inputs to the system to obtain the desired effect on the output of the system
2484 questions
Questions about real numbers not expressible as the quotient of two integers. For questions on determining whether a number is irrational, use the (rationality-testing) tag instead.
2478 questions
For questions involving random variables uniformly distributed on a subset of a measure space. To be used with [probability] or [probability-theory] tag.
2467 questions
For questions related to the binomial theorem, which describes the algebraic expansion of powers of binomials.
2455 questions
The science of compressing and communicating information. It is a branch of applied mathematics and electrical engineering. Though originally the focus was on digital communications and computing, it now finds wide use in biology, physics and other sciences.
2449 questions
For questions on random walks, a mathematical formalization of a path that consists of a succession of random steps.
2425 questions