Commit 2025-08-06 11:02 093fce98
View on Github →feat(RepresentationTheory/Homological/GroupHomology/Functoriality): the degree 1 part of the corestriction-coinflation exact sequence when the subgroup acts trivially (#25952)
Given a normal subgroup S of G and a G-representation A on which S acts trivially, this PR defines the short complex
H₁(S, A) ⟶ H₁(G, A) ⟶ H₁(G ⧸ S, A) induced by the natural inclusion S → G and projection G → G / S. We show it is exact and that the righthand map is an epimorphism.