Tags
A tag is a keyword or label that categorizes your question with other, similar questions.
Fractal analysis involves the study measures on fractals and their applications. This includes the study of self-similar integration and differential equations on fractals.
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For questions about the Eulerian numbers $A_{n,k}$, defined as the number of permutations in the symmetric group $S_n$ having $k$ descents. Not to be confused with Euler’s number $e$ or the Euler numbers $E_n$.
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Use this tag for questions about (1) in group theory, expressing a permutation in terms of its constituent cycles, (2) in commutative algebra and linear algebra, writing a finitely generated module over a principal ideal domain as the direct sum of cyclic modules and one free module, or (3) in graph theory, partitioning the vertices of a graph into subsets such that the vertices in each subset lie on a cycle.
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An example of a total computable function that is not primitive recursive; appears in the literature in many variants. The original three-argument variant can be used to define the Ackermann numbers.
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A totally unimodular matrix is a matrix for which every square non-singular submatrix is unimodular.
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Let $G$ be a finite group, typically $\mathbb{Z}/n \mathbb{Z}$, and $g\in G$. The multiplicative order of $g$ is the least $n\in\mathbb{N}^+$ such that $g^n = e$, the identity of $G$.
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Integral dependence (also known as algebraic dependence) is a condition on ring extensions $R\subseteq S$: we say $s\in S$ is integral over $R$ if there is some $f(x) \in R[x]$ such that $f(s)=0$.
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Problems that involve partitioning a geometric figure into smaller pieces with certain conditions on them (equal area, equal shape, possible to be rearranged into another given figure, etc.)
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The box topology is the topology on the cartesian product of sets generated by the cartesian product of open subsets in each component set. Use this tag when your question involves the box topology.
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For questions about secant lines, which are lines that pass through two points on some curve.
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The Schur decomposition of a complex matrix $A$ is of the form $A = Q U Q^*$, where matrix $Q$ is unitary and $U$ is an upper triangular matrix whose diagonal elements are the eigenvalues of $A$.
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This tag is for questions relating to weighted least squares, a generalization of ordinary least squares and linear regression in which the errors covariance matrix is allowed to be different from an identity matrix.
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A symmetric space is a differentiable manifold with the additional structure of a pseudo-Riemannian metric and which has many isometries.
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Summation by parts for discrete variables is the equivalent of integration by parts for continuous variables.
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is for Reliability Engineering and Reliability Theory that describes the probability of a system to complete its expected function during an interval of time. The engineering is an area focused on optimising the reliability or the probability of successful functioning, of systems such as graphs, percolations and mechanical systems such as airplanes. Originally a tool for insurance companies but nowadays more general interdisciplinary research area.
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This tag is for questions regarding the Hecke algebra or, Iwahori Hecke algebra, which is the algebra generated by Hecke operators.
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Use this tag for questions about those quantities that provide an alternative to the moments of a probability distribution.
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A subgroup of a group is characteristic in it if every automorphism of the whole group takes the subgroup within itself. To be used with the tag [group-theory].
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For questions about pattern matching in computer science, which is the act of checking a given sequence of tokens for the presence of the constituents of some pattern.
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A Padé approximation is the use of a ratio of polynomials to approximate a function. This can be seen as a generalization of the Taylor series which can better account for singularities in the function.
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Laplace expansion is a method for expanding determinants in terms of minors, determinants of some related smaller matrices.
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In abstract algebra, the transcendence degree of a field extension $L/K$ is a certain rather coarse measure of the “size” of the extension. Specifically, it is defined as the largest cardinality of an algebraically independent subset of $L$ over $K$.
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Topological dynamics is a subfield of the area of dynamical systems. The main focus is properties of dynamical systems that can be formulated using topological objects.
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A quasigroup is a grouplike structure $(Q, \ast)$, that satisfies the Latin square property but need not have an identity element, nor need it be associative. It coincides with the notion of a divisible magma.
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For questions on kronecker symbols, a generalization of the Jacobi symbol to all integers.
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The Farey sequence of order $n$ is the sequence of all lowest-terms fractions between 0 and 1 whose denominators do not exceed $n$, in increasing order.
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For questions on deconvolution, the resolution of a convolution function into the functions from which it was formed in order to separate their effects.
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Proofs that are partially or entirely checked by computer, including those formalised in interactive theorem provers.
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A unimodular matrix is a matrix whose determinant is $\pm 1$. Often, but not always, its entries are integers.
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Two measures are said to be singular w.r.t. each other if they are supported on disjoint sets.
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