ﻻ يوجد ملخص باللغة العربية
The multiple Birkhoff recurrence theorem states that for any $dinmathbb N$, every system $(X,T)$ has a multiply recurrent point $x$, i.e. $(x,x,ldots, x)$ is recurrent under $tau_d=:Ttimes T^2times ldots times T^d$. It is natural to ask if there always is a multiply minimal point, i.e. a point $x$ such that $(x,x,ldots,x)$ is $tau_d$-minimal. A negative answer is presented in this paper via studying the horocycle flows. However, it is shown that for any minimal system $(X,T)$ and any non-empty open set $U$, there is $xin U$ such that ${nin{mathbb Z}: T^nxin U, ldots, T^{dn}xin U}$ is piecewise syndetic; and that for a PI minimal system, any $M$-subsystem of $(X^d, tau_d)$ is minimal.
We investigate some connectedness properties of the set of points K(f) where the iterates of an entire function f are bounded. In particular, we describe a class of transcendental entire functions for which an analogue of the Branner-Hubbard conjectu
In this note a notion of generalized topological entropy for arbitrary subsets of the space of all sequences in a compact topological space is introduced. It is shown that for a continuous map on a compact space the generalized topological entropy of
Katznelsons Question is a long-standing open question concerning recurrence in topological dynamics with strong historical and mathematical ties to open problems in combinatorics and harmonic analysis. In this article, we give a positive answer to Ka
We define shadowable points for homeomorphism on metric spaces. In the compact case we will prove the following results: The set of shadowable points is invariant, possibly nonempty or noncompact. A homeomorphism has the pseudo-orbit tracing property
Let $f$ be a polynomial map of the Riemann sphere of degree at least two. We prove that if $f$ has a Siegel disk $G$ on which the rotation number satisfies a diophantine condition, then the boundary of $G$ contains a critical point.