2006-11-17

Vladimir Retakh, Rutgers University

Noncommutative loops over Lie algebras and Lie groups

In this talk I will introduce noncommutative loops over Lie algebras as a tool for studying algebraic groups over noncommutative rings.

Given a Lie algebra g sitting inside an associative algebra A and any associative algebra F, the F-loop algebra is the Lie subalgebra of tensor product F\otimes A generated by F\otimes g.

For a large class of Lie algebras g, including semisimple ones, there is an explicit description of all F-loop algebras. This description has a striking resemblance to the commutator expansions of F used by M. Kapranov in his approach to noncommutative geometry.

I will also define and study Lie groups associated with F-loop algebras. This is a joint paper with A. Berenstein (Univ. of Oregon).