{ "id": "2202.09336", "version": "v1", "published": "2022-02-18T18:04:59.000Z", "updated": "2022-02-18T18:04:59.000Z", "title": "Absolute continuity and singularity of spectra for flows $T_t\\otimes T_{at}$", "authors": [ "Valery V. Ryzhikov" ], "comment": "in Russian language", "categories": [ "math.DS" ], "abstract": "Answering the question of V.I. Oseledets, we present a random variable $\\xi$ such that the sum $\\xi(x)+a\\xi(y)$ has a singular distribution for a set of parameters $a$ dense in $(1, +\\infty)$, but for another dense set of parameters, this sum has an absolutely continuous distribution. We prove the following assertion: given $C,D$, countable non-intersecting dense subsets of the ray $(1,+\\infty)$, there is a measure-preserving flow $T_t$ (acting on the infinite Lebesgue space) such that automorphisms $T_1\\otimes T_{c}$ have simple singular spectra for every $c\\in C$, and $T_1\\otimes T_{d}$ have Lebesgue spectra for all $d\\in D$. The spectral measure of this flow plays the role of the distribution of our random variable $\\xi$.", "revisions": [ { "version": "v1", "updated": "2022-02-18T18:04:59.000Z" } ], "analyses": { "keywords": [ "absolute continuity", "singularity", "simple singular spectra", "infinite lebesgue space", "singular distribution" ], "note": { "typesetting": "TeX", "pages": 0, "language": "ru", "license": "arXiv", "status": "editable" } } }