Varieties of Representations of Finitely Generated Groups

Download or read book Varieties of Representations of Finitely Generated Groups written by Alexander Lubotzky and published by American Mathematical Soc.. This book was released on 1985 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: The n-dimensional representations, over an algebraically closed characteristic zero field k, of a finitely generated group are parameterized by an affine algebraic variety over k. The tangent spaces of this variety are subspaces of spaces of one-cocycles and thus the geometry of the variety is locally related to the cohomology of the group. The cohomology is also related to the prounipotent radical of the proalgebraic hull of the group. This paper exploits these two relations to compute dimensions of representation varieties, especially for nilpotent groups and their generalizations. It also presents the foundations of the theory of representation varieties in an expository, self-contained manner.