# 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.

An approximation algorithm is an algorithm that finds an approximate solution to a (typically NP-hard) problem. The quality of the algorithm is measured by how close to the actual optimum it performs…

In algebraic geometry, a projective variety over an algebraically closed field $k$ is a subset of some projective $n$-space $\mathbb P^n$ over $k$ that is the zero-locus of some finite family of homog…

for questions regarding to the Pseudo-differential operator, acting on a space of functions on a differentiable manifold, that can locally be described by definite rules using a certain fu…

the branch of mathematics that deals with the mathematical aspects of problems from science and engineering: applied analysis, numerical mathematics, applied statistics etc. (For applications of mathe…

Topological vector space with a locally convex topology, i.e. induced by a system of seminorms.

Use for questions about mirror symmetry in theoretical/mathematical physics.

for questions requesting advice (e.g. on a suitable publishing venue, presentation strategy, career move, ethical dilemma). It should be used in conjunction with a more specific tag, such …

Applications of mathematics to any field inside or outside mathematics

The study of formal languages (sets of strings or trees over an alphabet), rewriting systems and algorithms, recognition automata/algorithms, and related questions.

The Weyl group of a root system is a subgroup generated by reflections through the hyperplanes orthogonal to the roots.

The Prime Number Theorem is a theorem that describes the distribution of the primes. It says that the number of primes less than or equal to a real number $x$ is asymptotic to $\frac{x}{\ln x}$.

Stability theory, including global stability (in dynamical systems, where it can notably be used in combination with ds.dynamical-systems)

The loop space $Ω_X$ of a pointed topological space $X$ is the space of based maps from the circle $\mathbb S^1$ to $X$ with the compact-open topology.

Equivariant homotopy theory is the study of how homotopy theory behaves when spaces are considered together with a group action on them.

For questions about projective modules over a ring and projective objects in related categories.

Calabi-Yau manifolds are higher dimensional generalizations of elliptic curves and K3 surfaces. They can be defined as the compact complex Kähler manifolds with trivial canonical bundle, and play a ce…