Trivial cocycles and invariants of homology 3-spheres

Autor: Wolfgang Pitsch
Rok vydání: 2009
Předmět:
Zdroj: Advances in Mathematics. 220(1):278-302
ISSN: 0001-8708
DOI: 10.1016/j.aim.2008.09.002
Popis: We study the relationship between trivial cocycles on the Torelli group and invariants of oriented integral homology 3-spheres. We give ncecessary and sufficient conditions for a function defined on the union of the Torelli groups to be an invariant of homology spheres. We apply this study to give a new purely algebraic construction of the Casson invariant and prove in this setting its surgery properties. As a by-product we get a new 2-torsion cohomology class in the second integral cohomology of the Torelli group.
Comment: 25 pages, 12 figures
Databáze: OpenAIRE