Feng and Huang [Variational principle for weighted topological pressure. J. Math. Pures Appl. (9)106 (2016), 411–452] introduced weighted topological entropy and pressure for factor maps between dynamical systems and established its variational principle. Tsukamoto [New approach to weighted topological entropy and pressure. Ergod. Th. & Dynam. Sys.43 (2023), 1004–1034] redefined those invariants quite differently for the simplest case and showed via the variational principle that the two definitions coincide. We generalize Tsukamoto’s approach, redefine the weighted topological entropy and pressure for higher dimensions, and prove the variational principle. Our result allows for an elementary calculation of the Hausdorff dimension of affine-invariant sets such as self-affine sponges and certain sofic sets that reside in Euclidean space of arbitrary dimension.
Feng and Huang [Variational principle for weighted topological pressure.J. Math.Pures Appl. (9)106 (2016),411-452] 引入了动态系统间因子映射的加权拓扑熵和压力,并建立了其变分原理。Tsukamoto [New approach to weighted topological entropy and pressure.Ergod.Th. & Dynam.Sys.43(2023),1004-1034] 对最简单情况下的这些不变式进行了完全不同的重新定义,并通过变分原理证明这两个定义是重合的。我们推广了塚本的方法,重新定义了更高维度的加权拓扑熵和压力,并证明了变分原理。我们的结果允许对仿射不变集的豪斯多夫维度进行基本计算,如自仿射海绵和驻留在任意维度欧几里得空间中的某些索菲克集。
{"title":"Weighted topological pressure revisited","authors":"NIMA ALIBABAEI","doi":"10.1017/etds.2024.35","DOIUrl":"https://doi.org/10.1017/etds.2024.35","url":null,"abstract":"Feng and Huang [Variational principle for weighted topological pressure. <jats:italic>J. Math. Pures Appl. (9)</jats:italic>106 (2016), 411–452] introduced weighted topological entropy and pressure for factor maps between dynamical systems and established its variational principle. Tsukamoto [New approach to weighted topological entropy and pressure. <jats:italic>Ergod. Th. & Dynam. Sys.</jats:italic>43 (2023), 1004–1034] redefined those invariants quite differently for the simplest case and showed via the variational principle that the two definitions coincide. We generalize Tsukamoto’s approach, redefine the weighted topological entropy and pressure for higher dimensions, and prove the variational principle. Our result allows for an elementary calculation of the Hausdorff dimension of affine-invariant sets such as self-affine sponges and certain sofic sets that reside in Euclidean space of arbitrary dimension.","PeriodicalId":50504,"journal":{"name":"Ergodic Theory and Dynamical Systems","volume":"100 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140931000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We prove the convergence of moments of the number of directions of affine lattice vectors that fall into a small disc, under natural Diophantine conditions on the shift. Furthermore, we show that the pair correlation function is Poissonian for any irrational shift in dimension 3 and higher, including well-approximable vectors. Convergence in distribution was already proved in the work of Strömbergsson and the second author [The distribution of free path lengths in the periodic Lorentz gas and related lattice point problems. Ann. of Math. (2)172 (2010), 1949–2033], and the principal step in the extension to convergence of moments is an escape of mass estimate for averages over embedded $operatorname {SL}(d,mathbb {R})$ -horospheres in the space of affine lattices.
{"title":"Poissonian pair correlation for directions in multi-dimensional affine lattices and escape of mass estimates for embedded horospheres","authors":"WOOYEON KIM, JENS MARKLOF","doi":"10.1017/etds.2024.31","DOIUrl":"https://doi.org/10.1017/etds.2024.31","url":null,"abstract":"We prove the convergence of moments of the number of directions of affine lattice vectors that fall into a small disc, under natural Diophantine conditions on the shift. Furthermore, we show that the pair correlation function is Poissonian for <jats:italic>any</jats:italic> irrational shift in dimension 3 and higher, including well-approximable vectors. Convergence in distribution was already proved in the work of Strömbergsson and the second author [The distribution of free path lengths in the periodic Lorentz gas and related lattice point problems. <jats:italic>Ann. of Math. (2)</jats:italic>172 (2010), 1949–2033], and the principal step in the extension to convergence of moments is an escape of mass estimate for averages over embedded <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0143385724000312_inline1.png\"/> <jats:tex-math> $operatorname {SL}(d,mathbb {R})$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>-horospheres in the space of affine lattices.","PeriodicalId":50504,"journal":{"name":"Ergodic Theory and Dynamical Systems","volume":"101 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140800664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We prove a Khintchine-type recurrence theorem for pairs of endomorphisms of a countable discrete abelian group. As a special case of the main result, if <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" xlink:href="S0143385724000294_inline1.png"/> <jats:tex-math> $Gamma $ </jats:tex-math> </jats:alternatives> </jats:inline-formula> is a countable discrete abelian group, <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" xlink:href="S0143385724000294_inline2.png"/> <jats:tex-math> $varphi , psi in mathrm {End}(Gamma )$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>, and <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" xlink:href="S0143385724000294_inline3.png"/> <jats:tex-math> $psi - varphi $ </jats:tex-math> </jats:alternatives> </jats:inline-formula> is an injective endomorphism with finite index image, then for any ergodic measure-preserving <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" xlink:href="S0143385724000294_inline4.png"/> <jats:tex-math> $Gamma $ </jats:tex-math> </jats:alternatives> </jats:inline-formula>-system <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" xlink:href="S0143385724000294_inline5.png"/> <jats:tex-math> $( X, {mathcal {X}}, mu , (T_g)_{g in Gamma } )$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>, any measurable set <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" xlink:href="S0143385724000294_inline6.png"/> <jats:tex-math> $A in {mathcal {X}}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>, and any <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" xlink:href="S0143385724000294_inline7.png"/> <jats:tex-math> ${varepsilon }> 0$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>, there is a syndetic set of <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" xlink:href="S0143385724000294_inline8.png"/> <jats:tex-math> $g in Gamma$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> such that <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" xlink:href="S0143385724000294_inline9.png"/> <jats:tex-math> $mu ( A cap T_{varphi(g)}^{-1} A cap T_{psi(g)}^{-1} A ) > mu(A)^3 - varepsilon$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>. This generalizes the main results of Ackelsberg <jats:italic>et al</jats:italic> [Khintchine-type recurrence for 3-point configurations. <jats:italic
我们证明了可数离散无边群的成对内定态的欣钦钦型递推定理。作为主结果的一个特例,如果 $Gamma $ 是一个可数离散无边群, $varphi , psi in mathrm {End}(Gamma )$ 、并且 $psi - varphi $ 是一个具有有限索引映像的注入式内形变,那么对于任何保全遍历度量的 $Gamma $ 系统 $( X, {mathcal {X}}, mu , (T_g)_{g in Gamma } )$, 任何可度量集合 $g in Gamma } )$, 任何可度量集合 $g - varphi $ 是一个具有有限索引映像的注入式内形变。)$,{mathcal {X}}$中的任意可测集$A,以及任意${varepsilon }>;0$, there is a syndetic set of $g in Gamma$ such that $mu ( A cap T_{varphi(g)}^{-1} A cap T_{psi(g)}^{-1} A ) > mu(A)^3 - varepsilon$ .这概括了 Ackelsberg 等人[Khintchine-type recurrence for 3-point configurations.Forum Math.Sigma10 (2022), Paper no. e107] 并基本上回答了该论文中的一个未决问题 [Question 1.12; Khintchine-type recurrence for 3-point configurations.论坛数学。Sigma10 (2022), Paper no.]对于$Gamma = {mathbb {Z}}^d$ 群,结果适用于由差值为非奇异值的矩阵给出的成对内定态。证明的关键要素是(1) 与 Bergelson 和 Shalom 共同获得的最新结果[Khintchine-type recurrence for 3-point configurations.Forum Math.Sigma10 (2022), Paper no. e107]说,相关的遍历平均值由一个与准阿芬系数(或康泽-勒格朗系数)密切相关的特征因子控制;(2) 一个扩展技巧,以还原到具有良好离散谱(关于 $varphi $ 和 $psi $)的系统;(3) 描述与具有良好离散谱的旋转系统上的准阿芬环相关的麦基群。
{"title":"Khintchine-type double recurrence in abelian groups","authors":"ETHAN ACKELSBERG","doi":"10.1017/etds.2024.29","DOIUrl":"https://doi.org/10.1017/etds.2024.29","url":null,"abstract":"We prove a Khintchine-type recurrence theorem for pairs of endomorphisms of a countable discrete abelian group. As a special case of the main result, if <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0143385724000294_inline1.png\"/> <jats:tex-math> $Gamma $ </jats:tex-math> </jats:alternatives> </jats:inline-formula> is a countable discrete abelian group, <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0143385724000294_inline2.png\"/> <jats:tex-math> $varphi , psi in mathrm {End}(Gamma )$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>, and <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0143385724000294_inline3.png\"/> <jats:tex-math> $psi - varphi $ </jats:tex-math> </jats:alternatives> </jats:inline-formula> is an injective endomorphism with finite index image, then for any ergodic measure-preserving <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0143385724000294_inline4.png\"/> <jats:tex-math> $Gamma $ </jats:tex-math> </jats:alternatives> </jats:inline-formula>-system <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0143385724000294_inline5.png\"/> <jats:tex-math> $( X, {mathcal {X}}, mu , (T_g)_{g in Gamma } )$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>, any measurable set <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0143385724000294_inline6.png\"/> <jats:tex-math> $A in {mathcal {X}}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>, and any <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0143385724000294_inline7.png\"/> <jats:tex-math> ${varepsilon }> 0$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>, there is a syndetic set of <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0143385724000294_inline8.png\"/> <jats:tex-math> $g in Gamma$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> such that <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0143385724000294_inline9.png\"/> <jats:tex-math> $mu ( A cap T_{varphi(g)}^{-1} A cap T_{psi(g)}^{-1} A ) > mu(A)^3 - varepsilon$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>. This generalizes the main results of Ackelsberg <jats:italic>et al</jats:italic> [Khintchine-type recurrence for 3-point configurations. <jats:italic","PeriodicalId":50504,"journal":{"name":"Ergodic Theory and Dynamical Systems","volume":"51 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140800661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
DZMITRY BADZIAHIN, STEPHEN HARRAP, EREZ NESHARIM, DAVID SIMMONS
Schmidt games and the Cantor winning property give alternative notions of largeness, similar to the more standard notions of measure and category. Being intuitive, flexible, and applicable to recent research made them an active object of study. We survey the definitions of the most common variants and connections between them. A new game called the Cantor game is invented and helps with presenting a unifying framework. We prove surprising new results such as the coincidence of absolute winning and $1$ Cantor winning in metric spaces, and the fact that $1/2$ winning implies absolute winning for subsets of $mathbb {R}$ . We also suggest a prototypical example of a Cantor winning set to show the ubiquity of such sets in metric number theory and ergodic theory.
{"title":"Schmidt games and Cantor winning sets","authors":"DZMITRY BADZIAHIN, STEPHEN HARRAP, EREZ NESHARIM, DAVID SIMMONS","doi":"10.1017/etds.2024.23","DOIUrl":"https://doi.org/10.1017/etds.2024.23","url":null,"abstract":"Schmidt games and the Cantor winning property give alternative notions of largeness, similar to the more standard notions of measure and category. Being intuitive, flexible, and applicable to recent research made them an active object of study. We survey the definitions of the most common variants and connections between them. A new game called the Cantor game is invented and helps with presenting a unifying framework. We prove surprising new results such as the coincidence of absolute winning and <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0143385724000233_inline1.png\" /> <jats:tex-math> $1$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> Cantor winning in metric spaces, and the fact that <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0143385724000233_inline2.png\" /> <jats:tex-math> $1/2$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> winning implies absolute winning for subsets of <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0143385724000233_inline3.png\" /> <jats:tex-math> $mathbb {R}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>. We also suggest a prototypical example of a Cantor winning set to show the ubiquity of such sets in metric number theory and ergodic theory.","PeriodicalId":50504,"journal":{"name":"Ergodic Theory and Dynamical Systems","volume":"38 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140623891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We study the joint distribution of values of a pair consisting of a quadratic form <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" xlink:href="S0143385724000300_inline1.png" /> <jats:tex-math> ${mathbf q}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> and a linear form <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" xlink:href="S0143385724000300_inline2.png" /> <jats:tex-math> ${mathbf l}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> over the set of integral vectors, a problem initiated by Dani and Margulis [Orbit closures of generic unipotent flows on homogeneous spaces of <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" xlink:href="S0143385724000300_inline3.png" /> <jats:tex-math> $mathrm{SL}_3(mathbb{R})$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>. <jats:italic>Math. Ann.</jats:italic>286 (1990), 101–128]. In the spirit of the celebrated theorem of Eskin, Margulis and Mozes on the quantitative version of the Oppenheim conjecture, we show that if <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" xlink:href="S0143385724000300_inline4.png" /> <jats:tex-math> $n ge 5$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>, then under the assumptions that for every <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" xlink:href="S0143385724000300_inline5.png" /> <jats:tex-math> $(alpha , beta ) in {mathbb {R}}^2 setminus { (0,0) }$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>, the form <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" xlink:href="S0143385724000300_inline6.png" /> <jats:tex-math> $alpha {mathbf q} + beta {mathbf l}^2$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> is irrational and that the signature of the restriction of <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" xlink:href="S0143385724000300_inline7.png" /> <jats:tex-math> ${mathbf q}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> to the kernel of <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" xlink:href="S0143385724000300_inline8.png" /> <jats:tex-math> ${mathbf l}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> is <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" xlink:href="S0143385724000300_inline9.png" /> <jats:tex-math> $(p, n-1-p)$ </jats:tex-math> </jats:alternatives> </jats:inline-formu
我们研究由积分向量集合上的二次形式 ${mathbf q}$ 和线性形式 ${mathbf l}$ 组成的一对值的联合分布,这个问题由 Dani 和 Margulis [Orbit closures of generic unipotent flows on homogeneous spaces of $mathrm{SL}_3(mathbb{R})$ .Math.Ann.286 (1990), 101-128].本着埃斯金、马格里斯和莫泽斯关于奥本海姆猜想定量版的著名定理的精神,我们证明了如果 $n ge 5$ , 那么在对每一个 $(alpha , beta ) in {mathbb{R}}^2 setminus { (0,0) }$ 的假设下,形式为 $alpha {mathbf q}.+ β {mathbf l}^2$ 是无理的,并且 ${mathbf q}$ 对 ${mathbf l}$ 内核的限制的签名是 $(p, n-1-p)$ ,其中 ${3le ple n-2}$ ,在 {mathbb {Z}}^n$ 中,$|v| <;T$ , $a < {mathbf q}(v) < b$ 和 $c< {mathbf l}(v) <;d$ 在 $T to infty $ 时渐近为 $ C({mathbf q}, {mathbf l})(d-c)(b-a)T^{n-3}$ ,其中 $C({mathbf q}, {mathbf l})$ 只取决于 ${mathbf q}$ 和 ${mathbf l}$ 。Gorodnik[Oppenheim conjecture for pairs consisting of a linear form and a quadatic form.Trans.Amer.Math.Soc.356(11) (2004), 4447-4463].
{"title":"Asymptotic distribution for pairs of linear and quadratic forms at integral vectors","authors":"JIYOUNG HAN, SEONHEE LIM, KEIVAN MALLAHI-KARAI","doi":"10.1017/etds.2024.30","DOIUrl":"https://doi.org/10.1017/etds.2024.30","url":null,"abstract":"We study the joint distribution of values of a pair consisting of a quadratic form <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0143385724000300_inline1.png\" /> <jats:tex-math> ${mathbf q}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> and a linear form <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0143385724000300_inline2.png\" /> <jats:tex-math> ${mathbf l}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> over the set of integral vectors, a problem initiated by Dani and Margulis [Orbit closures of generic unipotent flows on homogeneous spaces of <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0143385724000300_inline3.png\" /> <jats:tex-math> $mathrm{SL}_3(mathbb{R})$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>. <jats:italic>Math. Ann.</jats:italic>286 (1990), 101–128]. In the spirit of the celebrated theorem of Eskin, Margulis and Mozes on the quantitative version of the Oppenheim conjecture, we show that if <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0143385724000300_inline4.png\" /> <jats:tex-math> $n ge 5$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>, then under the assumptions that for every <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0143385724000300_inline5.png\" /> <jats:tex-math> $(alpha , beta ) in {mathbb {R}}^2 setminus { (0,0) }$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>, the form <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0143385724000300_inline6.png\" /> <jats:tex-math> $alpha {mathbf q} + beta {mathbf l}^2$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> is irrational and that the signature of the restriction of <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0143385724000300_inline7.png\" /> <jats:tex-math> ${mathbf q}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> to the kernel of <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0143385724000300_inline8.png\" /> <jats:tex-math> ${mathbf l}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> is <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0143385724000300_inline9.png\" /> <jats:tex-math> $(p, n-1-p)$ </jats:tex-math> </jats:alternatives> </jats:inline-formu","PeriodicalId":50504,"journal":{"name":"Ergodic Theory and Dynamical Systems","volume":"49 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140609087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pavlov [Adv. Math.295 (2016), 250–270; Nonlinearity32 (2019), 2441–2466] studied the measures of maximal entropy for dynamical systems with weak versions of specification property and found the existence of intrinsic ergodicity would be influenced by the assumptions of the gap functions. Inspired by these, in this article, we study the dynamical systems with non-uniform specification property. We give some basic properties these systems have and give an assumption for the gap functions to ensure the systems have the following five properties: CO-measures are dense in invariant measures; for every non-empty compact connected subset of invariant measures, its saturated set is dense in the total space; ergodic measures are residual in invariant measures; ergodic measures are connected; and entropy-dense. In addition, we will give examples to show the assumption is optimal.
{"title":"Similarities and differences between specification and non-uniform specification","authors":"WANSHAN LIN, XUETING TIAN, CHENWEI YU","doi":"10.1017/etds.2024.28","DOIUrl":"https://doi.org/10.1017/etds.2024.28","url":null,"abstract":"Pavlov [<jats:italic>Adv. Math.</jats:italic>295 (2016), 250–270; <jats:italic>Nonlinearity</jats:italic>32 (2019), 2441–2466] studied the measures of maximal entropy for dynamical systems with weak versions of specification property and found the existence of intrinsic ergodicity would be influenced by the assumptions of the gap functions. Inspired by these, in this article, we study the dynamical systems with non-uniform specification property. We give some basic properties these systems have and give an assumption for the gap functions to ensure the systems have the following five properties: CO-measures are dense in invariant measures; for every non-empty compact connected subset of invariant measures, its saturated set is dense in the total space; ergodic measures are residual in invariant measures; ergodic measures are connected; and entropy-dense. In addition, we will give examples to show the assumption is optimal.","PeriodicalId":50504,"journal":{"name":"Ergodic Theory and Dynamical Systems","volume":"86 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140589962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We prove that a generic probability measure-preserving (p.m.p.) action of a countable amenable group G has scaling entropy that cannot be dominated by a given rate of growth. As a corollary, we obtain that there does not exist a topological action of G for which the set of ergodic invariant measures coincides with the set of all ergodic p.m.p. G-systems of entropy zero. We also prove that a generic action of a residually finite amenable group has scaling entropy that cannot be bounded from below by a given sequence. In addition, we show an example of an amenable group that has such a lower bound for every free p.m.p. action.
我们证明,可数可合并群 G 的一般概率度量保留(p.m.p. )作用的缩放熵不能被给定的增长率所支配。作为推论,我们得到不存在一个 G 的拓扑作用,其遍历不变度量集合与熵为零的所有遍历 p.m.p. G 系统的集合重合。我们还证明了残差有限可调和群的泛函作用具有无法通过给定序列从下往上限定的缩放熵。此外,我们还展示了一个例子,说明可亲群的每个自由 p.m.p. 作用都有这样的下限。
{"title":"Non-existence of a universal zero-entropy system via generic actions of almost complete growth","authors":"GEORGII VEPREV","doi":"10.1017/etds.2024.24","DOIUrl":"https://doi.org/10.1017/etds.2024.24","url":null,"abstract":"We prove that a generic probability measure-preserving (p.m.p.) action of a countable amenable group <jats:italic>G</jats:italic> has scaling entropy that cannot be dominated by a given rate of growth. As a corollary, we obtain that there does not exist a topological action of <jats:italic>G</jats:italic> for which the set of ergodic invariant measures coincides with the set of all ergodic p.m.p. <jats:italic>G</jats:italic>-systems of entropy zero. We also prove that a generic action of a residually finite amenable group has scaling entropy that cannot be bounded from below by a given sequence. In addition, we show an example of an amenable group that has such a lower bound for every free p.m.p. action.","PeriodicalId":50504,"journal":{"name":"Ergodic Theory and Dynamical Systems","volume":"214 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140589934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We show that, generically, the unique invariant measure of a sufficiently regular piecewise smooth circle homeomorphism with irrational rotation number and zero mean nonlinearity (e.g. piecewise linear) has zero Hausdorff dimension. To encode this generic condition, we consider piecewise smooth homeomorphisms as generalized interval exchange transformations (GIETs) of the interval and rely on the notion of combinatorial rotation number for GIETs, which can be seen as an extension of the classical notion of rotation number for circle homeomorphisms to the GIET setting.
{"title":"On the Hausdorff dimension of invariant measures of piecewise smooth circle homeomorphisms","authors":"FRANK TRUJILLO","doi":"10.1017/etds.2024.25","DOIUrl":"https://doi.org/10.1017/etds.2024.25","url":null,"abstract":"We show that, generically, the unique invariant measure of a sufficiently regular piecewise smooth circle homeomorphism with irrational rotation number and zero mean nonlinearity (e.g. piecewise linear) has zero Hausdorff dimension. To encode this generic condition, we consider piecewise smooth homeomorphisms as <jats:italic>generalized interval exchange transformations</jats:italic> (GIETs) of the interval and rely on the notion of <jats:italic>combinatorial rotation number</jats:italic> for GIETs, which can be seen as an extension of the classical notion of rotation number for circle homeomorphisms to the GIET setting.","PeriodicalId":50504,"journal":{"name":"Ergodic Theory and Dynamical Systems","volume":"272 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140589963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We define a notion of substitution on colored binary trees that we call substreetution. We show that a point fixed by a substreetution may (or not) be almost periodic, and thus the closure of the orbit under the $mathbb {F}_{2}^{+}$ -action may (or not) be minimal. We study one special example: we show that it belongs to the minimal case and that the number of preimages in the minimal set increases just exponentially fast, whereas it could be expected a super-exponential growth. We also give examples of periodic trees without invariant measures on their orbit. We use our construction to get quasi-periodic colored tilings of the hyperbolic disk.
{"title":"Substreetutions and more on trees","authors":"ALEXANDRE BARAVIERA, RENAUD LEPLAIDEUR","doi":"10.1017/etds.2023.108","DOIUrl":"https://doi.org/10.1017/etds.2023.108","url":null,"abstract":"We define a notion of substitution on colored binary trees that we call substreetution. We show that a point fixed by a substreetution may (or not) be almost periodic, and thus the closure of the orbit under the <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0143385723001086_inline1.png\" /> <jats:tex-math> $mathbb {F}_{2}^{+}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>-action may (or not) be minimal. We study one special example: we show that it belongs to the minimal case and that the number of preimages in the minimal set increases just exponentially fast, whereas it could be expected a super-exponential growth. We also give examples of periodic trees without invariant measures on their orbit. We use our construction to get quasi-periodic colored tilings of the hyperbolic disk.","PeriodicalId":50504,"journal":{"name":"Ergodic Theory and Dynamical Systems","volume":"67 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140589959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We show that the mode-locking region of the family of quasi-periodically forced Arnold circle maps with a topologically generic forcing function is dense. This gives a rigorous verification of certain numerical observations in [M. Ding, C. Grebogi and E. Ott. Evolution of attractors in quasiperiodically forced systems: from quasiperiodic to strange nonchaotic to chaotic. Phys. Rev. A 39(5) (1989), 2593–2598] for such forcing functions. More generally, under some general conditions on the base map, we show the density of the mode-locking property among dynamically forced maps (defined in [Z. Zhang. On topological genericity of the mode-locking phenomenon. Math. Ann. 376 (2020), 707–72]) equipped with a topology that is much stronger than the $C^0$ topology, compatible with smooth fiber maps. For quasi-periodic base maps, our result generalizes the main results in [A. Avila, J. Bochi and D. Damanik. Cantor spectrum for Schrödinger operators with potentials arising from generalized skew-shifts. Duke Math. J.146 (2009), 253–280], [J. Wang, Q. Zhou and T. Jäger. Genericity of mode-locking for quasiperiodically forced circle maps. Adv. Math.348 (2019), 353–377] and Zhang (2020).
我们证明,具有拓扑通用强迫函数的准周期强迫阿诺德圆图族的锁模区是密集的。这就严格验证了 [M. Ding, C. Grebogi and E. Ott.Ding, C. Grebogi and E. Ott.准周期强迫系统吸引子的演化:从准周期到奇异非混沌再到混沌。Phys. Rev. A 39(5) (1989),2593-2598] 对于这类强迫函数。更一般地说,在基图的一些一般条件下,我们展示了动态强迫图(定义见 [Z. Zhang.Zhang.On topological genericity of the mode-locking phenomenon.Math.Ann.376 (2020), 707-72])配备的拓扑比 $C^0$ 拓扑强得多,与光滑光纤映射兼容。对于准周期基底映射,我们的结果概括了 [A. Avila, J. Bochi and J. M. Matters] 中的主要结果。Avila, J. Bochi and D. Damanik.薛定谔算子的康托谱系与广义偏移产生的势[A. Avila, J. Bochi and D. Damanik.Duke Math.J.146(2009),253-280],[J.Wang, Q. Zhou and T. Jäger.准周期强迫圆图的锁模属性.Adv. Math.348 (2019), 353-377] 和 Zhang (2020).
{"title":"Density of mode-locking property for quasi-periodically forced Arnold circle maps","authors":"JIAN WANG, ZHIYUAN ZHANG","doi":"10.1017/etds.2024.27","DOIUrl":"https://doi.org/10.1017/etds.2024.27","url":null,"abstract":"We show that the mode-locking region of the family of quasi-periodically forced Arnold circle maps with a topologically generic forcing function is dense. This gives a rigorous verification of certain numerical observations in [M. Ding, C. Grebogi and E. Ott. Evolution of attractors in quasiperiodically forced systems: from quasiperiodic to strange nonchaotic to chaotic. <jats:italic>Phys. Rev. A</jats:italic> 39(5) (1989), 2593–2598] for such forcing functions. More generally, under some general conditions on the base map, we show the density of the mode-locking property among dynamically forced maps (defined in [Z. Zhang. On topological genericity of the mode-locking phenomenon. <jats:italic>Math. Ann.</jats:italic> 376 (2020), 707–72]) equipped with a topology that is much stronger than the <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0143385724000270_inline1.png\" /> <jats:tex-math> $C^0$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> topology, compatible with smooth fiber maps. For quasi-periodic base maps, our result generalizes the main results in [A. Avila, J. Bochi and D. Damanik. Cantor spectrum for Schrödinger operators with potentials arising from generalized skew-shifts. <jats:italic>Duke Math. J.</jats:italic>146 (2009), 253–280], [J. Wang, Q. Zhou and T. Jäger. Genericity of mode-locking for quasiperiodically forced circle maps. <jats:italic>Adv. Math.</jats:italic>348 (2019), 353–377] and Zhang (2020).","PeriodicalId":50504,"journal":{"name":"Ergodic Theory and Dynamical Systems","volume":"28 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140589952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}