Subject: question for list: bar construction over a semisimple ring From: John H Palmieri Date: Mon, 09 Apr 2007 11:47:55 -0700 Here's a question for the topology mailing list: Is there anything in the literature about the bar construction for an algebra over a semisimple ring? For instance, suppose that k is a field, R is a ring which is a sum of copies of k, and A is an "algebra" over R: I put algebra in quotes because R need not be central in A -- this is one of the complicating factors. I would like to construct the bar construction B(A) (as well as B(A;M), etc.) and to have the usual facts about it. Has anyone worked this out and written it down anywhere? Comments: - In the cases I care about right now, R is commutative, but we should probably allow it to be noncommutative. - Also in the cases I care about, A is graded "connected" and R is the degree zero part of A. In particular, there is an augmentation map A --> R, so I have an augmentation ideal; thus I can try to work with reduced or unreduced versions of the bar construction. - Why not generalize more? Let R be a possibly noncommutative k-algebra, let A be an R-algebra (with R non-central), and perhaps suppose that A is flat over R. If you like, suppose that A is non-negatively graded and that R is the degree zero part of A. Thanks, John -- J. H. Palmieri Associate Professor of Mathematics University of Washington Box 354350, Seattle, WA 98195-4350 palmieri@math.washington.edu http://www.math.washington.edu/~palmieri/