{"title":"沿多项式的所有阶的拓扑轻度混合","authors":"Yang Cao, S. Shao","doi":"10.3934/dcds.2021150","DOIUrl":null,"url":null,"abstract":"<p style='text-indent:20px;'>A minimal system <inline-formula><tex-math id=\"M1\">\\begin{document}$ (X,T) $\\end{document}</tex-math></inline-formula> is topologically mildly mixing if for all non-empty open subsets <inline-formula><tex-math id=\"M2\">\\begin{document}$ U,V $\\end{document}</tex-math></inline-formula>, <inline-formula><tex-math id=\"M3\">\\begin{document}$ \\{n\\in {\\mathbb Z}: U\\cap T^{-n}V\\neq \\emptyset\\} $\\end{document}</tex-math></inline-formula> is an IP<inline-formula><tex-math id=\"M4\">\\begin{document}$ ^* $\\end{document}</tex-math></inline-formula>-set. In this paper we show that if a minimal system is topologically mildly mixing, then it is mild mixing of all orders along polynomials. That is, suppose that <inline-formula><tex-math id=\"M5\">\\begin{document}$ (X,T) $\\end{document}</tex-math></inline-formula> is a topologically mildly mixing minimal system, <inline-formula><tex-math id=\"M6\">\\begin{document}$ d\\in {\\mathbb N} $\\end{document}</tex-math></inline-formula>, <inline-formula><tex-math id=\"M7\">\\begin{document}$ p_1(n),\\ldots, p_d(n) $\\end{document}</tex-math></inline-formula> are integral polynomials with no <inline-formula><tex-math id=\"M8\">\\begin{document}$ p_i $\\end{document}</tex-math></inline-formula> and no <inline-formula><tex-math id=\"M9\">\\begin{document}$ p_i-p_j $\\end{document}</tex-math></inline-formula> constant, <inline-formula><tex-math id=\"M10\">\\begin{document}$ 1\\le i\\neq j\\le d $\\end{document}</tex-math></inline-formula>. Then for all non-empty open subsets <inline-formula><tex-math id=\"M11\">\\begin{document}$ U , V_1, \\ldots, V_d $\\end{document}</tex-math></inline-formula>, <inline-formula><tex-math id=\"M12\">\\begin{document}$ \\{n\\in {\\mathbb Z}: U\\cap T^{-p_1(n) }V_1\\cap T^{-p_2(n)}V_2\\cap \\ldots \\cap T^{-p_d(n) }V_d \\neq \\emptyset \\} $\\end{document}</tex-math></inline-formula> is an IP<inline-formula><tex-math id=\"M13\">\\begin{document}$ ^* $\\end{document}</tex-math></inline-formula>-set. We also give the corresponding theorem for systems under abelian group actions.</p>","PeriodicalId":11254,"journal":{"name":"Discrete & Continuous Dynamical Systems - S","volume":"13 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2021-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Topological mild mixing of all orders along polynomials\",\"authors\":\"Yang Cao, S. Shao\",\"doi\":\"10.3934/dcds.2021150\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p style='text-indent:20px;'>A minimal system <inline-formula><tex-math id=\\\"M1\\\">\\\\begin{document}$ (X,T) $\\\\end{document}</tex-math></inline-formula> is topologically mildly mixing if for all non-empty open subsets <inline-formula><tex-math id=\\\"M2\\\">\\\\begin{document}$ U,V $\\\\end{document}</tex-math></inline-formula>, <inline-formula><tex-math id=\\\"M3\\\">\\\\begin{document}$ \\\\{n\\\\in {\\\\mathbb Z}: U\\\\cap T^{-n}V\\\\neq \\\\emptyset\\\\} $\\\\end{document}</tex-math></inline-formula> is an IP<inline-formula><tex-math id=\\\"M4\\\">\\\\begin{document}$ ^* $\\\\end{document}</tex-math></inline-formula>-set. In this paper we show that if a minimal system is topologically mildly mixing, then it is mild mixing of all orders along polynomials. That is, suppose that <inline-formula><tex-math id=\\\"M5\\\">\\\\begin{document}$ (X,T) $\\\\end{document}</tex-math></inline-formula> is a topologically mildly mixing minimal system, <inline-formula><tex-math id=\\\"M6\\\">\\\\begin{document}$ d\\\\in {\\\\mathbb N} $\\\\end{document}</tex-math></inline-formula>, <inline-formula><tex-math id=\\\"M7\\\">\\\\begin{document}$ p_1(n),\\\\ldots, p_d(n) $\\\\end{document}</tex-math></inline-formula> are integral polynomials with no <inline-formula><tex-math id=\\\"M8\\\">\\\\begin{document}$ p_i $\\\\end{document}</tex-math></inline-formula> and no <inline-formula><tex-math id=\\\"M9\\\">\\\\begin{document}$ p_i-p_j $\\\\end{document}</tex-math></inline-formula> constant, <inline-formula><tex-math id=\\\"M10\\\">\\\\begin{document}$ 1\\\\le i\\\\neq j\\\\le d $\\\\end{document}</tex-math></inline-formula>. Then for all non-empty open subsets <inline-formula><tex-math id=\\\"M11\\\">\\\\begin{document}$ U , V_1, \\\\ldots, V_d $\\\\end{document}</tex-math></inline-formula>, <inline-formula><tex-math id=\\\"M12\\\">\\\\begin{document}$ \\\\{n\\\\in {\\\\mathbb Z}: U\\\\cap T^{-p_1(n) }V_1\\\\cap T^{-p_2(n)}V_2\\\\cap \\\\ldots \\\\cap T^{-p_d(n) }V_d \\\\neq \\\\emptyset \\\\} $\\\\end{document}</tex-math></inline-formula> is an IP<inline-formula><tex-math id=\\\"M13\\\">\\\\begin{document}$ ^* $\\\\end{document}</tex-math></inline-formula>-set. We also give the corresponding theorem for systems under abelian group actions.</p>\",\"PeriodicalId\":11254,\"journal\":{\"name\":\"Discrete & Continuous Dynamical Systems - S\",\"volume\":\"13 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2021-03-19\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Discrete & Continuous Dynamical Systems - S\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.3934/dcds.2021150\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Discrete & Continuous Dynamical Systems - S","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.3934/dcds.2021150","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
摘要
A minimal system \begin{document}$ (X,T) $\end{document} is topologically mildly mixing if for all non-empty open subsets \begin{document}$ U,V $\end{document}, \begin{document}$ \{n\in {\mathbb Z}: U\cap T^{-n}V\neq \emptyset\} $\end{document} is an IP\begin{document}$ ^* $\end{document}-set. In this paper we show that if a minimal system is topologically mildly mixing, then it is mild mixing of all orders along polynomials. That is, suppose that \begin{document}$ (X,T) $\end{document} is a topologically mildly mixing minimal system, \begin{document}$ d\in {\mathbb N} $\end{document}, \begin{document}$ p_1(n),\ldots, p_d(n) $\end{document} are integral polynomials with no \begin{document}$ p_i $\end{document} and no \begin{document}$ p_i-p_j $\end{document} constant, \begin{document}$ 1\le i\neq j\le d $\end{document}. Then for all non-empty open subsets \begin{document}$ U , V_1, \ldots, V_d $\end{document}, \begin{document}$ \{n\in {\mathbb Z}: U\cap T^{-p_1(n) }V_1\cap T^{-p_2(n)}V_2\cap \ldots \cap T^{-p_d(n) }V_d \neq \emptyset \} $\end{document} is an IP\begin{document}$ ^* $\end{document}-set. We also give the corresponding theorem for systems under abelian group actions.
Topological mild mixing of all orders along polynomials
A minimal system \begin{document}$ (X,T) $\end{document} is topologically mildly mixing if for all non-empty open subsets \begin{document}$ U,V $\end{document}, \begin{document}$ \{n\in {\mathbb Z}: U\cap T^{-n}V\neq \emptyset\} $\end{document} is an IP\begin{document}$ ^* $\end{document}-set. In this paper we show that if a minimal system is topologically mildly mixing, then it is mild mixing of all orders along polynomials. That is, suppose that \begin{document}$ (X,T) $\end{document} is a topologically mildly mixing minimal system, \begin{document}$ d\in {\mathbb N} $\end{document}, \begin{document}$ p_1(n),\ldots, p_d(n) $\end{document} are integral polynomials with no \begin{document}$ p_i $\end{document} and no \begin{document}$ p_i-p_j $\end{document} constant, \begin{document}$ 1\le i\neq j\le d $\end{document}. Then for all non-empty open subsets \begin{document}$ U , V_1, \ldots, V_d $\end{document}, \begin{document}$ \{n\in {\mathbb Z}: U\cap T^{-p_1(n) }V_1\cap T^{-p_2(n)}V_2\cap \ldots \cap T^{-p_d(n) }V_d \neq \emptyset \} $\end{document} is an IP\begin{document}$ ^* $\end{document}-set. We also give the corresponding theorem for systems under abelian group actions.