scholarly journals Recurrence on affine Grassmannians

2018 ◽  
Vol 39 (12) ◽  
pp. 3207-3223
Author(s):  
YVES BENOIST ◽  
CAROLINE BRUÈRE

We study the action of the affine group $G$ of $\mathbb{R}^{d}$ on the space $X_{k,\,d}$ of $k$-dimensional affine subspaces. Given a compactly supported Zariski dense probability measure $\unicode[STIX]{x1D707}$ on $G$, we show that $X_{k,d}$ supports a $\unicode[STIX]{x1D707}$-stationary measure $\unicode[STIX]{x1D708}$ if and only if the $(k+1)\text{th}$ Lyapunov exponent of $\unicode[STIX]{x1D707}$ is strictly negative. In particular, when $\unicode[STIX]{x1D707}$ is symmetric, $\unicode[STIX]{x1D708}$ exists if and only if $2k\geq d$.

Analysis ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Bilel Selmi

Abstract This paper studies the behavior of the lower and upper multifractal Hewitt–Stromberg functions under slices onto ( n - m ) {(n-m)} -dimensional subspaces. More precisely, we discuss the relationship between the multifractal Hewitt–Stromberg functions of a compactly supported Borel probability measure and those of slices or sections of the measure. In addition, we prove that if μ has a finite m-energy and q lies in a certain somewhat restricted interval, then these functions satisfy the expected adding of co-dimensions formula.


2011 ◽  
Vol 48 (3) ◽  
pp. 778-791 ◽  
Author(s):  
Harry Crane

We study a family of Markov processes on P(k), the space of partitions of the natural numbers with at most k blocks. The process can be constructed from a Poisson point process on R+ x ∏i=1kP(k) with intensity dt ⊗ ϱν(k), where ϱν is the distribution of the paintbox based on the probability measure ν on Pm, the set of ranked-mass partitions of 1, and ϱν(k) is the product measure on ∏i=1kP(k). We show that these processes possess a unique stationary measure, and we discuss a particular set of reversible processes for which transition probabilities can be written down explicitly.


2011 ◽  
Vol 48 (03) ◽  
pp. 778-791 ◽  
Author(s):  
Harry Crane

We study a family of Markov processes onP(k), the space of partitions of the natural numbers with at mostkblocks. The process can be constructed from a Poisson point process onR+x ∏i=1kP(k)with intensity dt⊗ ϱν(k), where ϱνis the distribution of the paintbox based on the probability measure ν onPm, the set of ranked-mass partitions of 1, and ϱν(k)is the product measure on ∏i=1kP(k). We show that these processes possess a unique stationary measure, and we discuss a particular set of reversible processes for which transition probabilities can be written down explicitly.


2021 ◽  
pp. 1-40
Author(s):  
ALENA ERCHENKO

Abstract We consider a smooth area-preserving Anosov diffeomorphism $f\colon \mathbb T^2\rightarrow \mathbb T^2$ homotopic to an Anosov automorphism L of $\mathbb T^2$ . It is known that the positive Lyapunov exponent of f with respect to the normalized Lebesgue measure is less than or equal to the topological entropy of L, which, in addition, is less than or equal to the Lyapunov exponent of f with respect to the probability measure of maximal entropy. Moreover, the equalities only occur simultaneously. We show that these are the only restrictions on these two dynamical invariants.


2017 ◽  
Vol 38 (6) ◽  
pp. 2180-2223 ◽  
Author(s):  
TALIA FERNÓS

We show under weak hypotheses that $\unicode[STIX]{x2202}X$, the Roller boundary of a finite-dimensional CAT(0) cube complex $X$ is the Furstenberg–Poisson boundary of a sufficiently nice random walk on an acting group $\unicode[STIX]{x1D6E4}$. In particular, we show that if $\unicode[STIX]{x1D6E4}$ admits a non-elementary proper action on $X$, and $\unicode[STIX]{x1D707}$ is a generating probability measure of finite entropy and finite first logarithmic moment, then there is a $\unicode[STIX]{x1D707}$-stationary measure on $\unicode[STIX]{x2202}X$ making it the Furstenberg–Poisson boundary for the $\unicode[STIX]{x1D707}$-random walk on $\unicode[STIX]{x1D6E4}$. We also show that the support is contained in the closure of the regular points. Regular points exhibit strong contracting properties.


2011 ◽  
Vol 1 (9) ◽  
pp. 53-55
Author(s):  
Abinash Dahal ◽  
◽  
Deepashree Devaraj ◽  
Dr. N. Pradhan Dr. N. Pradhan

2013 ◽  
Vol 50 (2) ◽  
pp. 258-265
Author(s):  
Pál Hegedűs

In this paper we analyse the natural permutation module of an affine permutation group. For this the regular module of an elementary Abelian p-group is described in detail. We consider the inequivalent permutation modules coming from nonconjugate complements. We prove their strong structural similarity well exceeding the fact that they have equal Brauer characters.


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