Classical groups
Finite groups
Group schemes
Topological groups
Lie groups
Super-Lie groups
Higher groups
Cohomology and Extensions
Related concepts
abstract duality: opposite category,
concrete duality: dual object, dualizable object, fully dualizable object, dualizing object
Examples
between higher geometry/higher algebra
Langlands duality, geometric Langlands duality, quantum geometric Langlands duality
In QFT and String theory
Pontryagin duality restricts to an equivalence of categories between abelian profinite groups and (the opposite of) abelian torsion groups
Notice that for a profinite group then and so one usually writes this equivalence as
is dual to the profinite completion of the integers . And so the canonical map is dual to .
The abelian group underlying the p-adic integers is Pontryagin dual to the Prüfer p-group .
Jean-Pierre Serre, section 1.1. of Galois cohomology
Ramakrishnan, Valenza, Fourier analysis on number fields
Clark Barwick, Exercises on locally compact abelian groups: An invitation to harmonic analysis (pdf)
Last revised on January 22, 2020 at 12:15:00. See the history of this page for a list of all contributions to it.