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.
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motives× 191 
computationalgeometry× 189
Using computers to solve geometric problems. Questions with this tag should typically have at least one other tag indicating what sort of geometry is involved, such as ag.algebraicgeometry or mg.metr…

characteristicp× 186  hodgetheory× 186 
teaching× 186
For questions related to teaching mathematics. For questions in Mathematics Education as a scientific discipline there is also the tag mathematicseducation. Note you may also ask your question on htt…

manifolds× 183  algebraicsurfaces× 182  stablehomotopy× 182 
birationalgeometry× 181 
hilbertspaces× 176
a real or complex vector space endowed with an inner product such that $H$ is a complete metric space when endowed with the norm induced by this inner product.

convexoptimization× 175
Optimization with convex constraints and convex objectives; notions related to convex optimization such as subgradients, normal cones, separating hyperplanes

euclideangeometry× 174 
randomwalk× 173 
riemannzetafunction× 171
the function of one complex variable $s$ defined by the series $\zeta(s) = \sum_{n \geq 1} \frac{1}{n^s}$ when $\operatorname{Re}(s)>1$. It admits a meromorphic continuati…

mathphilosophy× 169  monoidalcategories× 167 
textbookrecommendation× 164
Questions asking for recommendations of textbooks on some subject. It can be helpful to indicate whether the request is for selfstudy, for use in a course one teaches, for use accompanying a course o…

differentialoperators× 160
Elliptic, parabolic and hyperbolic operators. Laplace, LaplaceBeltrami, Schrödinger, Dirac. Exterior derivative and Lie derivative operators.

groupactions× 160  eigenvalues× 159 
calculusofvariations× 159  semigroups× 156 
lfunctions× 155
Questions about generalizations of the Riemann Zeta function of arithmetic interest whose definition relies on meromorphic continuation of special kinds of Dirichlet series, such as Dirichlet Lfuncti…

prooftheory× 152
For question in Proof Theory, where "proofs" themselves are the object of mathematical investigation. It is not to be used to request a proof of some result.

langlandsconjectures× 150
Higher reciprocity laws

computeralgebra× 150
Using computers to solve algebraic problems. Questions with this tag should typically include at least one other tag indicating what sort of algebraic problem is involved, such as ac.commutativealgeb…

graphcolorings× 148  classfieldtheory× 147 
homology× 147  zetafunctions× 146 
universalalgebra× 145
The study of algebraic structures and properties applying to large classes of such structures. For example, ideas from group theory and ring theory are extended and considered for structures with oth…

geometricmeasuretheory× 145
Questions about geometric properties of sets using measure theoretic techniques; rectifiability of sets and measures, currents, Plateau problem, isoperimetric inequality and related topics.

planegeometry× 144 
spectralgraphtheory× 144
Questions related to the spectrum of graphs, defined using one of the possible variants of the discrete Laplace operator or Laplacian matrix.
See https://en.wikipedia.org/wiki/Discrete_Laplace_oper…

gm.generalmathematics× 143  intersectiontheory× 140 