Weight zero part of the first cohomology of complex algebraic varieties
arXiv:1804.03632
Abstract
We show that the weight 0 part of the first cohomology of a complex algebraic variety is a topological invariant, and give an explicit description of its dimension using a topological construction of the normalization of , where can be reducible, but must be equidimensional. The first assertion is known in the compact case by A. Weber, where intersection cohomology is used. Note that the weight 1 or 2 part of the first cohomology is not a topological (or even analytic) invariant in the non-compact case by Serre's example.
16 page