Gerstenhaber duality in Hochschild cohomology

Let C be a differential graded chain coalgebra, &UOmega; C the reduced cobar construction on C and C-V the dual algebra. We prove that for a large class of coalgebras C there is a natural isomorphism of Gerstenhaber algebras between the Hochschild cohomologies, HH*(C-V, C-V) and HH*(&UOmega; C; &UOmega; C). This result yields to a Hodge decomposition of the loop space homology of a closed oriented manifold, when the field of coefficients is of characteristic zero. © 2004 Elsevier B.V. All rights reserved.