TY - JOUR
T1 - Noncommutative de Rham cohomology of finite groups
AU - Castellani, L.
AU - Catenacci, R.
AU - Debernardi, M.
AU - Pagani, C.
N1 - Funding Information:
∗Supported in part by the European Commission RTN programme HPRN-CT-2000-00131 and by MIUR under contract 2001-025492.
PY - 2004/5/10
Y1 - 2004/5/10
N2 - We study de Rham cohomology for various differential calculi on finite groups G up to order 8. These include the permutation group S3, the dihedral group D4 and the quaternion group Q. Poincaré duality holds in every case, and under some assumptions (essentially the existence of a top form) we find that it must hold in general. A short review of the bicovariant (noncommutative) differential calculus on finite G is given for selfconsistency. Exterior derivative, exterior product, metric, Hodge dual, connections, torsion, curvature, and biinvariant integration can be defined algebraically. A projector decomposition of the braiding operator is found, and used in constructing the projector on the space of two-forms. By means of the braiding operator and the metric a knot invariant is defined for any finite group.
AB - We study de Rham cohomology for various differential calculi on finite groups G up to order 8. These include the permutation group S3, the dihedral group D4 and the quaternion group Q. Poincaré duality holds in every case, and under some assumptions (essentially the existence of a top form) we find that it must hold in general. A short review of the bicovariant (noncommutative) differential calculus on finite G is given for selfconsistency. Exterior derivative, exterior product, metric, Hodge dual, connections, torsion, curvature, and biinvariant integration can be defined algebraically. A projector decomposition of the braiding operator is found, and used in constructing the projector on the space of two-forms. By means of the braiding operator and the metric a knot invariant is defined for any finite group.
KW - De Rham cohomology
KW - Finite groups
KW - Noncommutative geometry
UR - http://www.scopus.com/inward/record.url?scp=10844268253&partnerID=8YFLogxK
U2 - 10.1142/S0217751X04018403
DO - 10.1142/S0217751X04018403
M3 - Short survey
SN - 0217-751X
VL - 19
SP - 1961
EP - 1986
JO - International Journal of Modern Physics A
JF - International Journal of Modern Physics A
IS - 12
ER -