[ m at h . Q A ] 1 5 O ct 2 00 4 ON RACK COHOMOLOGY
نویسندگان
چکیده
We prove that the lower bounds for Betti numbers of the rack, quandle and degeneracy cohomol-ogy given in [CJKS] are in fact equalities. We compute as well the Betti numbers of the twisted cohomology introduced in [CES]. We also give a group-theoretical interpretation of the second cohomology group for racks.
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