A fusion system of a $p$-group $P$ is the category of subgroups of $P$ and injective group homomorphisms induced by conjugation in $P$. Example topics include control of fusion, blocks, centric and radical subgroups, subsystems and quotients, Alperin's fusion theorem, and normal fusion systems.
A fusion system of a $p$-group $P$ is the category of subgroups of $P$ and injective group homomorphisms induced by conjugation in $P$. Example topics include control of fusion, blocks, centric and radical subgroups, subsystems and quotients, Alperin's fusion theorem, and normal fusion systems.
For an introduction to the theory, see David A. Craven's lecture notes, or this paper by Markus Linckelmann. There is a MathOverflow thread about applications.
