摘要
We generalize the classical Hilbert-Mumford criteria for GIT (semi-)stability in terms of one parameter subgroups of a linearly reductive group G over a field k, to the relative situation of an equivariant, projective morphism to a noetherian k-algebra A. We also extend the classical projectivity result for GIT quotients: the induced morphism is projective. As an example of applications to moduli problems, we consider degenerations of Hilbert schemes of points.
- 出版日期2015-11