Tags
A tag is a keyword or label that categorizes your question with other, similar questions.
Characteristic classes are invariants of bundles living in the cohomology of the base. The most common examples of characteristic classes are the Chern, Stiefel–Whitney, and Pontryagin classes.
701 questions
For questions about type theory, including normalization, dependent types, identity types, inductive types, universe types, functional programming languages, proofs as programs in simply-typed lambda-calculi, Martin-Löf's intuitionistic type theory or related.Consider using one of the following tags: (lambda-calculus), (logic), (constructive-mathematics),(homotopy-type-theory) if related.
700 questions
Questions about Pythagorean triples, positive integer solutions to $a^2 + b^2 = c^2$.
699 questions
In algebra, a nested radical is a radical expression (one containing a square root sign, cube root sign, etc.) that contains (nests) another radical expression.
691 questions
For question about weak derivatives, a notion which extends the classical notion of derivative and allows us to consider derivatives of distributions rather than functions.
690 questions
Queueing theory is the mathematical study of waiting lines, or queues.
689 questions
For questions concerning the Cantor set, which consists of those real numbers in $ [0,1]$ that remain after repeatedly removing the open middle third of every interval; it contains those numbers which may be written in ternary without using 1. Also, for questions about other topological spaces that are homeomorphic to the Cantor set.
688 questions
A commutative ring with unity in which every nonzero, nonunit element can be written as a product of irreducible elements, and where such product is unique up to ordering and associates. Also called UFD or "factorial ring"
687 questions
For questions about elliptic partial differential equations. If your question is specific to the Laplace equation, see (harmonic-functions).
682 questions
For questions about Galois extensions of fields. We say that an algebraic extension $L/K$ is a Galois extension iff the subfield of $L$ that is fixed by automorphisms of $L$ which fix K is exactly $K$.
679 questions
Questions on the topic of NP-Completeness, which comes from Theoretical Computer Science
676 questions
This tag should be used for questions about isomorphisms between vector spaces.
674 questions
Use this tag for question on path-connected spaces and related notions. These include locally path-connected spaces, arcwise connected spaces and so on. For the more general notion, use the (connectedness) tag.
674 questions
For questions on or related to the technique of Gaussian elimination, used in solving systems of linear equations.
674 questions
Regular expressions or Regex is a search pattern for strings defined by a sequence of characters.
673 questions
For questions about general quadrilaterals (including parallelograms, trapezoids, rhombi) and their properties.
672 questions
In mathematics, a submanifold of a manifold $M$ is a subset $S$ which itself has the structure of a manifold, and for which the inclusion map $S \rightarrow M$ satisfies certain properties. There are different types of submanifolds depending on exactly which properties are required. Different authors often have different definitions. Therefore, please include the details when using this tag.
670 questions
This tag is for questions about a Green's function which is the impulse response of an inhomogeneous differential equation defined on a domain, with specified initial conditions or boundary conditions.
669 questions
Class field theory is a major branch of algebraic number theory that studies abelian extensions of global and local fields.
669 questions
For elementary questions concerning permutation cycles and permutation groups. This includes all representations of permutations (two-line arrays, cycles, bipartite graphs); transpositions and the sign/parity of a permutation; the Symmetric group and the Alternating group. To be used with the (permutations) tag to make the distinction between abstract algebra permutation questions and combinatoric permutation questions.
666 questions
Use for questions in Ramsey Theory, i.e. regarding how large a structure must be before it is guaranteed to have a certain property. Please be especially careful not to ask open questions in this tag.
662 questions
This tag is for questions that are asking for online resources in mathematics (references, dictionaries, encyclopaedic collections, online tools, videos and lectures, etc), or asking about the mathematics behind tools and technology found on the internet.
662 questions
Low-dimensional topology generally refers to the study of 3 or 4 dimensional topological manifolds and knot theory.
660 questions
The method of characteristics is a way of solving certain partial differential equations by reducing them to ordinary differential equations. It is most often used for 1st order equations. Use with the (pde) tag.
657 questions
A non-convex optimization problem is one where either the objective function is non-convex in a minimization problem (or non-concave in a maximization problem) or where the feasible region is not convex.
656 questions
For questions on the formal system in mathematical logic for expressing computation using abstract notions of functions and combining them through binding and substitution.
655 questions
Use with the (group-theory) tag. A group is simple if it has no proper, non-trivial normal subgroups. Equivalently (for finitely generated groups), its only homomorphic images are itself and the trivial group. The classification of finite simple groups is one of the great results of modern mathematics.
652 questions
Questions on elliptic integrals, integrals that involve the square root of a cubic or quartic polynomial.
650 questions
This tag is for the mathematics involved in the field of image processing. Many such questions are also appropriate for Signal Processing Stack Exchange.
649 questions
This tag is intended for questions on topics related to Baire category, such as Baire category theorem, meager sets (set of first category), nonmeager sets (set of second category), Baire spaces etc.
649 questions
Use with the (group-theory) tag. Refers to questions concerning finite groups of prime power order or infinite p-groups such as Prüfer groups, pro-p-groups, and Tarski monsters. This tag is not for p-adic number systems.
646 questions
Paradoxes are arguments which contradict logic or common sense, often by using false and implicit premises.
643 questions
For questions about the direct product of groups, rings, fields or categories. Use (group-theory), (ring-theory), (field-theory) or (category-theory).
643 questions
For questions related to cumulative distribution functions.
642 questions