Similar to ハミルトン-ヤコビ-ベルマン方程式

Atiyah–Singer index theorem

Sieve of Atkin

Apéry's constant

Apéry's theorem

Abel–Plana formula

Apollonius point

Apollonian gasket

Erlang distribution

Archimedes's cattle problem

Archimedean property

Twin circles

Algorithm

Artin L-function

Artin–Hasse exponential

Wedderburn–Artin theorem

Artinian module

Artinian ring

Artin–Schreier theory

Artin reciprocity

Artin–Rees lemma

Albanese variety

Alexander polynomial

List of things named after Alexander Grothendieck

Cayley–Hamilton theorem

Cauchy–Kovalevskaya theorem

Cauchy–Riemann equations