On the index of the quotient of a Borel subalgebra by an ad-nilpotent ideal
arXiv:0908.4201
Abstract
In this paper, we give upper bounds for the index of the quotient of the Borel subalgebra of a simple Lie algebra or its nilpotent radical by an ad-nilpotent ideal. For the nilpotent radical quotient, our bound is a generalization of the formula for the index given by Panov in the type A case. In general, this bound is not exact. Using results from Panov, we show that the upper bound for the Borel quotient is exact in the type case, and we conjecture that it is exact in general.
arXiv comment15 pages