文摘
We introduce a multiplicative version of complex-symplectic implosion in the case of \(\mathrm{SL}(n, {\mathbb C})\). The universal multiplicative implosion for \(\mathrm{SL}(n, {\mathbb C})\) is an affine variety and can be viewed as a nonreductive geometric invariant theory quotient. It carries a torus action and reductions by this action give the Steinberg fibres of \(\mathrm{SL}(n, {\mathbb C})\). We also explain how the real symplectic group-valued universal implosion introduced by Hurtubise, Jeffrey and Sjamaar may be identified inside this space. Keywords Implosion Hyperk?hler Nonreductive quotient