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A Homotopy Equivalence for Partition Posets Related to Liftings of Sn−1-Modules to Sn

✍ Scribed by Sheila Sundaram


Publisher
Elsevier Science
Year
2001
Tongue
English
Weight
146 KB
Volume
94
Category
Article
ISSN
0097-3165

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✦ Synopsis


We give a homotopy equivalence to explain an S n&1 -module isomorphism which occurs frequently in the homology of subposets of the partition lattice 6 n . The isomorphism in question is necessary for the existence of a lifting to S n of the S n&1 -module involved. It has also been observed in certain deformations of the free Lie algebra. The topological explanation allows us to generate further examples in subposets of 6 n . We show that, in these two contexts, it is often accompanied by an S n -action on the S n&1 -module occurring in the isomorphism. A well-known example is the lifting of the homology of 6 n&1 .