# 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:
 class-field-theory× 176 a major branch of algebraic number theory that studies abelian extensions of global and local fields. tiling× 176 for questions about (not necessarily periodic) tilings of metric spaces, their combinatorial, topological and dynamical properties, as well as basic definitions and concepts. golden-ratio× 175 Questions relating to the golden ratio $\varphi = \frac{1+\sqrt{5}}{2}$ newton-raphson× 175 for questions regarding the Newton–Raphson method. In numerical analysis the Newton–Raphson method is a method for finding successively better approximations to the roots (or zeroes) of a … principal-bundles× 174 a mathematical object which formalizes some of the essential features of the Cartesian product $X\times G$ of a space $X$ with a group $G$. infinitary-combinatorics× 174 For topics of a combinatorial character in set theory. Topics belonging to "combinatorial set theory" may be tagged this way. These include: Partition calculus, diamond principles, square principles, … type-theory× 174 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-… sorting× 173 For questions about dividing groups of objects based on their properties. hopf-algebras× 173 For questions about Hopf algebras and related concepts, such as quantum groups. holder-spaces× 173 for concepts related to Hölder continuity (a generalisation of Lipschitz continuity) and the related Hölder spaces. elliptic-functions× 173 Questions on doubly periodic functions on the complex plane such as Jacobi and Weierstrass elliptic functions. error-function× 173 for the error and complementary error functions (erf and erfc). These are special functions formed by taking definite integrals of the Gaussian/normal distribution function. block-matrices× 173 defined block wise, like $\pmatrix{A&B\\ C&D}$ where $A,B,C$ and $D$ are themselves matrices. Use this tag with (matrices), and often with (linear-algebra). convention× 172 for questions about standard, cultural practices in mathematics. absolute-convergence× 171 for questions related to absolute convergence a series. diophantine-approximation× 170 For questions about approximating real numbers by rational numbers. article-writing× 168 Various aspects of writing mathematics such as style, notation, grammar, frequently used phrases and common mistakes. nilpotence× 168 A nilpotent matrix has $A^n=0$ for some integer $n$. monoidal-categories× 168 In mathematics, a monoidal category (or tensor category) is a category C equipped with a bifunctor ⊗ : C × C → C which is associative up to a natural isomorphism, and an object I which is both a lef… reflection× 168 a transformation that fixes a line or plane or a more general subset. Reflections appear in geometry, linear algebra, complex analysis, differential equations, etc -- therefore, this ta… semidirect-product× 168 a construction in group theory generalizing the direct product. It arises as the structure of a group $G$ with a normal subgroup $N$ having a complement $N$. solvable-groups× 166 For questions on solvable groups, their properties, and structure. elliptic-integrals× 166 Questions on elliptic integrals, integrals that involve the square root of a cubic or quartic polynomial. network-flow× 165 For questions about networks that inhibit source and sink nodes and a notion of flow. optimal-control× 165 Optimal control theory, an extension of the calculus of variations, is a mathematical optimization method for deriving control policies. (Def: http://en.m.wikipedia.org/wiki/Optimal_control) infinitesimals× 164 For questions about infinitesimals, both in an intuitive sense as well as more rigorous settings (see also [nonstandard-analysis]). infinite-groups× 164 For questions about groups where the underlying set has infinite cardinality. graded-rings× 164 In mathematics, in particular abstract algebra, a graded ring is a ring that is a direct sum of abelian groups $R_i$ such that $R_i R_j \subset R_{i+j}$. (Def: http://en.m.wikipedia.org/wiki/Graded_ri… arithmetic-progressions× 164 Questions related to arithmetic progressions (sequences with a constant difference between the terms) catalan-numbers× 163 For questions on Catalan numbers, a sequence of natural numbers that occur in various counting problems. bernoulli-numbers× 162 Questions on Bernoulli numbers, a special sequence of rational numbers that arise as the coefficients in the power series expansions of certain elementary functions. branch-cuts× 161 curve in the complex extending from a branch point of the function. constants× 161 For questions about mathematical constants, that are "significantly interesting in some way". homogeneous-equation× 161 called homogeneous if the following condition is satisfied: If $\phi(x)$ is a solution, so is $c \phi(x)$, where c is an arbitrary (non-zero) constant. (Def: http:… quantum-groups× 161 In mathematics and theoretical physics, the term quantum group denotes various kinds of noncommutative algebra with additional structure. (Def: http://en.m.wikipedia.org/wiki/Quantum_group) riemann-hypothesis× 161 Questions on the Riemann hypothesis, a conjecture on the behavior of the complex zeros of the Riemann $\zeta$ function. You might want to add the tag [riemann-zeta] to your question as well.