{ "id": "1610.01438", "version": "v1", "published": "2016-10-05T14:25:36.000Z", "updated": "2016-10-05T14:25:36.000Z", "title": "On conservative sequences and their application to ergodic multiplier problems", "authors": [ "Madeleine Elyze", "Alexander Kastner", "Juan Ortiz Rhoton", "Vadim Semenov", "Cesar E. Silva" ], "comment": "26 pages, 3 figures", "categories": [ "math.DS" ], "abstract": "The \\emph{conservative sequence} of a set $A$ under a transformation $T$ is the set of all $n \\in \\mathbb{Z}$ such that $T^n A \\cap A \\not = \\varnothing$. By studying these sequences, we prove that given any countable collection of nonsingular transformations with no finite invariant measure $\\{T_i\\}$, there exists a rank-one transformation $S$ such that $T_i \\times S$ is not ergodic for all $i$. Moreover, $S$ can be chosen to be rigid or have infinite ergodic index. We establish similar results for $\\mathbb{Z}^d$ actions and flows. Then, we find sufficient conditions on rank-one transformations $T$ that guarantee the existence of a rank-one transformation $S$ such that $T \\times S$ is ergodic, or, alternatively, conditions that guarantee that $T \\times S$ is conservative but not ergodic. In particular, the infinite Chac\\'on transformation satisfies both conditions. Finally, for a given ergodic transformation $T$, we study the Baire categories of the sets $E(T)$, $\\bar{E}C(T)$ and $\\bar{C}(T)$ of transformations $S$ such that $T \\times S$ is ergodic, ergodic but not conservative, and conservative, respectively.", "revisions": [ { "version": "v1", "updated": "2016-10-05T14:25:36.000Z" } ], "analyses": { "keywords": [ "ergodic multiplier problems", "conservative sequences", "rank-one transformation", "infinite chacon transformation satisfies", "application" ], "note": { "typesetting": "TeX", "pages": 26, "language": "en", "license": "arXiv", "status": "editable" } } }