Properties of measures supported on fat Sierpinski carpets

In this paper we study certain conformal iterated function schemes in two dimensions that are natural generalizations of the Sierpinski carpet construction. In particular, we consider scaling factors for which the open set condition fails. For such ‘fat Sierpinski carpets’ we study the range of parameters for which the dimension of the set is exactly known, or for which the set has positive measure

An analogue of Bauer’s theorem for closed orbits of skew products

In this article we prove an analogue of Bauer’s theorem from algebraic number theory in the context of hyperbolic systems

Logarithm laws for equilibrium states in negative curvature

Let $M$ be a pinched negatively curved Riemannian manifold, whose unit tangent bundle is endowed with a Gibbs measure $m_F$ associated to a potential $F$. We compute the Hausdorff dimension of the conditional measures of $m_F$. We study the $m_F$-almost sure asymptotic penetration behaviour of locally geodesic lines of $M$ into small neighbourhoods of closed geodesics, and of other compact (locally) convex subsets of $M$. We prove Khintchine-type and logarithm law-type results for the spiraling of geodesic lines around these objects. As an arithmetic consequence, we give almost sure Diophantine approximation results of real numbers by quadratic irrationals with respect to general H\"older quasi-invariant measures

Addendum: an analogue of Artin reciprocity for closed orbits of skew products

One of the unfulfilled aims of the authors of the preceding paper [W. Parry and M. Pollicott. An analogue of Bauer’s theorem for closed orbits of skew products. Ergod. Th. & Dynam. Sys. 28 (2008), 535–546] was to find a dynamical analogue of Artin reciprocity. In this addendum, we present one such version, suggested by work of Sunada

Unique Bernoulli g-measures

We improve and subsume the conditions of Johansson and \"Oberg [18] and Berbee [2] for uniqueness of a g-measure, i.e., a stationary distribution for chains with complete connections. In addition, we prove that these unique g-measures have Bernoulli natural extensions. In particular, we obtain a unique g-measure that has the Bernoulli property for the full shift on finitely many states under any one of the following additional assumptions. (1) \sum_{n=1}^\infty (\var_n \log g)^20$, \sum_{n=1}^\infty e^{-(\{1}{2}+\epsilon) (\var_1 \log g+...+\var_n \log g)}=\infty,$$(3)$$\var_n \log g=\ordo{\{1}{\sqrt{n}}}, \quad n\to \infty.$$ That the measure is Bernoulli in the case of (1) is new. In (2) we have an improved version of Berbee's condition (concerning uniqueness and Bernoullicity) [2], allowing the variations of log g to be essentially twice as large. Finally, (3) is an example that our main result is new both for uniqueness and for the Bernoulli property. We also conclude that we have convergence in the Wasserstein metric of the iterates of the adjoint transfer operator to the g-measure

A note on the shrinking sector problem for surfaces of variable negative curvature

Given the universal cover for a compact surface of variable negative curvature we consider, for each k ≥ 0, the limiting probability for the directions in which a narrowing sector of unit area contains exactly k in the orbit of the covering group. This can be done relative to any Gibbs measure and follows directly from the strong mixing propert

Countable state shifts and uniqueness of g-measures

In this paper we present a new approach to studying g-measures which is based upon local absolute continuity. We extend the result in [11] that square summability of variations of g-functions ensures uniqueness of g-measures. The first extension is to the case of countably many symbols. The second extension is to some cases where $g \geq 0$, relaxing the earlier requirement in [11] that inf g>0.Comment: 11 page