Let k be an algebraically closed field and G a linear algebraic group over k acting rationally on a k-algebra V. Generalizing work of Moeglin and Rentschler in characteristic zero, we study the action of G on the spectrum of rational ideals of V. The main result is the following. Suppose that V is s
The Spectrum of Completely Positive Entropy Actions of Countable Amenable Groups
โ Scribed by A.H. Dooley; V.Ya. Golodets
- Publisher
- Elsevier Science
- Year
- 2002
- Tongue
- English
- Weight
- 189 KB
- Volume
- 196
- Category
- Article
- ISSN
- 0022-1236
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โฆ Synopsis
We prove that an ergodic free action of a countable discrete amenable group with completely positive entropy has a countable Lebesgue spectrum. Our approach is based on the Rudolph-Weiss result on the equality of conditional entropies for actions of countable amenable groups with the same orbits. Relative completely positive entropy actions are also considered. An application to the entropic properties of Gaussian actions of countable discrete abelian groups is given.
๐ SIMILAR VOLUMES
We study rational actions of a linear algebraic group G on an algebra V, and the ลฝ . ลฝ induced actions on Rat V , the spectrum of rational ideals of V a subset of ลฝ . . Spec V which often includes all primitive ideals . This work extends results of Moeglin and Rentschler to prime characteristic, oft