Dyer-Lashof-Cohen operations in Hochschild cohomology

We give explicit formulae for operations in Hochschild cohomology which are analogous to the operations in the homology of double loop spaces. As a corollary we obtain that any brace algebra in finite characteristic is always a restricted Lie algebra.Comment: This is the version published by Algebraic & Geometric Topology on 24 July 200

Homology of non-kk-overlapping discs

In this paper we describe the homology and cohomology of some natural bimodules over the little discs operad, whose components are configurations of non-$k$-overlapping discs. At the end we briefly explain how this algebraic structure intervenes in the study of spaces of non-$k$-equal immersions.Comment: 29 page