The age grading and the Chen-Ruan cup product
Algebraic Topology
2010-09-20 v3 Algebraic Geometry
Abstract
We prove that the obstruction bundle used to define the cup-product in Chen-Ruan cohomology is determined by the so-called `age grading' or `degree-shifting numbers'. Indeed, the obstruction bundle can be directly computed using the age grading. We obtain a Kunneth Theorem for Chen-Ruan cohomology as a direct consequence of an elementary property of the age grading, and explain how several other results - including associativity of the cup-product - can be proved in a similar way.
Cite
@article{arxiv.0706.4326,
title = {The age grading and the Chen-Ruan cup product},
author = {Richard A. Hepworth},
journal= {arXiv preprint arXiv:0706.4326},
year = {2010}
}