A categorical quotient in the category of dense constructible subsets
Abstract
Description
A. A'Campo-Neuen and J. Hausen gave an example of an algebraic torus action on an open subset of the affine four space that admits no quotient in the category of algebraic varieties. We show that this example admits a quotient in the category of dense constructible subsets and thereby answer a question of A. Bialynicki-Birula.
To appear in Colloquium Mathematicum
To appear in Colloquium Mathematicum