Bulletin of the London Mathematical Society Advance Access originally published online on March 12, 2008
Bulletin of the London Mathematical Society 2008 40(1):151-162; doi:10.1112/blms/bdm107
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© 2008 London Mathematical Society
Cluster-tilted algebras as trivial extensions
Département de Mathématiques
Université de Sherbrooke
Sherbrooke, Québec
Canada J1K 2R1
ibrahim.assem@usherbrooke.ca
Département de Mathématiques
Université de Sherbrooke
Sherbrooke, Québec
Canada J1K 2R1
and
Department of Mathematics
Bishop's University
Lennoxville, Québec
Canada J1M 1Z7
tbruestl@ubishops.ca
Department of Mathematics and Statistics
University of Massachusetts at Amherst
Amherst, MA 01003-9305
USA
schiffler@math.umass.edu
Received 22 January 2006. Revision received 20 March 2007.
Given a finite-dimensional algebra C (over an algebraically closed field) of global dimension at most two, we define its relation-extension algebra to be the trivial extension C Ext
(DC,C) of C by the C–C-bimodule Ext
(DC,C). We give a construction for the quiver of the relation-extension algebra in case the quiver of C has no oriented cycles. Our main result says that an algebra
is cluster-tilted if and only if there exists a tilted algebra C such that
is isomorphic to the relation-extension of C.
2000 Mathematics Subject Classification 16S70 (primary), 16G20 (secondary).
The first and the second author gratefully acknowledge partial support form the NSERC of Canada. The second author also thanks the universities of Sherbrooke and Bishop's for partial support. The third author was partially supported by the University of Massachusetts.