Unique range sets and uniqueness polynomials in positive characteristic
We denote by a field of characteristic zero satisfying . Let be a connected -split linear algebraic group acting on rationally by with a Zariski-dense -orbit . A prehomogeneous vector space ,X) is called “universally transitive” if the set of -rational points is a single
In the article we introduce a valuation function over a field [1]. Ring of non negative elements and its ideal of positive elements have been also defined.
We study asymptotic jumping numbers for graded sequences of ideals, and show that every such invariant is computed by a suitable real valuation of the function field. We conjecture that every valuation that computes an asymptotic jumping number is necessarily quasi-monomial. This conjecture holds in dimension two. In general, we reduce it to the case of affine space and to graded sequences of valuation ideals. Along the way, we study the structure of a suitable valuation space.
This paper deals with valuations of fields of formal meromorphic functions and their residue fields. We explicitly describe the residue fields of the monomial valuations. We also classify all the discrete rank one valuations of fields of power series in two and three variables, according to their residue fields. We prove that all our cases are possible and give explicit constructions.