Journal of the London Mathematical Society Advance Access originally published online on July 21, 2007
Journal of the London Mathematical Society 2007 75(3):718-740; doi:10.1112/jlms/jdm017
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© 2007 London Mathematical Society
Auslander algebras and initial seeds for cluster algebras
1 Instituto de Matemáticas
Universidad Nacional Autónoma de México
México D.F.
C.P. 04510
México
2 Mathematisches Institut
Universität Bonn
Beringstr. 1
53115 Bonn
Germany
jschroer{at}maths.leeds.ac.uk
3 Université de Caen
LMNO CNRS UMR 6139
F-14032 Caen cedex
France
leclerc{at}math.unicaen.fr
Let Q be a Dynkin quiver and
the corresponding set of positive roots. For the preprojective algebra
associated to Q, a rigid
-module IQ is produced with r = |
| pairwise non-isomorphic indecomposable direct summands by pushing the injective modules of the Auslander algebra of k Q to
. If N is a maximal unipotent subgroup of a complex simply connected simple Lie group of type |Q|, then the coordinate ring
[N] is an upper cluster algebra. It is shown that the elements of the dual semicanonical basis which correspond to the indecomposable direct summands of IQ coincide with certain generalized minors which form an initial cluster for
[N] and that the corresponding exchange matrix of this cluster can be read from the Gabriel quiver of End
(IQ). Finally, the fact that the categories of injective modules over
and over its covering
are triangulated is exploited in order to show several interesting identities in the respective stable module categories.
christof{at}matem.unam.mx
2000 Mathematics Subject Classification 14M99, 16D70, 16E20, 16G20, 16G70, 17B37, 20G42.
The first author acknowledges support from DGAPA grant IN101402-3. The second author is grateful to the CNRS networks GDR 2432 and the GDR 2249 for their support. The third author was supported by a research fellowship from the DFG.
Received September 2, 2005; revised August 24, 2006; published online July 21, 2007.