Hostname: page-component-6766d58669-nf276 Total loading time: 0 Render date: 2026-05-24T08:01:29.489Z Has data issue: false hasContentIssue false

Shrinking parallelepiped targets for $\beta $-dynamical systems

Published online by Cambridge University Press:  19 November 2024

YUBIN HE*
Affiliation:
Department of Mathematics, Shantou University, Shantou, Guangdong 515063, China
*

Abstract

For $ \beta>1 $, let $ T_\beta $ be the $\beta $-transformation on $ [0,1) $. Let $ \beta _1,\ldots ,\beta _d>1 $ and let $ \mathcal P=\{P_n\}_{n\ge 1} $ be a sequence of parallelepipeds in $ [0,1)^d $. Define

$$ \begin{align*}W(\mathcal P)=\{\mathbf{x}\in[0,1)^d:(T_{\beta_1}\times\cdots \times T_{\beta_d})^n(\mathbf{x})\in P_n\text{ infinitely often}\}.\end{align*} $$
When each $ P_n $ is a hyperrectangle with sides parallel to the axes, the ‘rectangle to rectangle’ mass transference principle by Wang and Wu [Mass transference principle from rectangles to rectangles in Diophantine approximation. Math. Ann. 381 (2021) 243–317] is usually employed to derive the lower bound for $\dim _{\mathrm {H}} W(\mathcal P)$, where $\dim _{\mathrm {H}}$ denotes the Hausdorff dimension. However, in the case where $ P_n $ is still a hyperrectangle but with rotation, this principle, while still applicable, often fails to yield the desired lower bound. In this paper, we determine the optimal cover of parallelepipeds, thereby obtaining $\dim _{\mathrm {H}} W(\mathcal P)$. We also provide several examples to illustrate how the rotations of hyperrectangles affect $\dim _{\mathrm {H}} W(\mathcal P)$.

Information

Type
Original Article
Copyright
© The Author(s), 2024. Published by Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable