Equilibrium Measures for Maps with Inducing Schemes

We introduce a class of continuous maps f of a compact metric space I admitting inducing schemes and describe the tower constructions associated with them. We then establish a thermodynamical formalism, i.e., describe a class of real-valued potential functions \phi on I which admit unique equilibrium measures \mu_\phi minimizing the free energy for a certain class of measures. We also describe ergodic properties of equilibrium measures including decay of correlation and the Central Limit Theorem. Our results apply in particular to some one-dimensional unimodal and multimodal maps as well as to multidimensional nonuniformly hyperbolic maps admitting Young's tower. Examples of potential functions to which our theory applies include \phi_t=-t\log|df| with t\in(t_0, t_1) for some t_0<1<t_1. In the particular case of S-unimodal maps we show that one can choose t_0<0 and that the class of measures under consideration comprises all invariant Borel probability measures. Thus our results establish existence and uniqueness of both the measure of maximal entropy (by a different method than Hofbauer) and the absolutely continuous invariant measure extending results by Bruin and Keller for the parameters under consideration

Affine actions of a free semigroup on the real line

We consider actions of the free semigroup with two generators on the real line, where the generators act as affine maps, one contracting and one expanding, with distinct fixed points. Then every orbit is dense in a half-line, which leads to the question whether it is, in some sense, uniformly distributed. We present answers to this question for various interpretations of the phrase ``uniformly distributed''

A new transatlantic trade war?: Issues surrounding the US-EU steel conflict

Six months after the Doha agreement on a new round of talks to liberalise world trade, tension is mounting between the EU and the US, the world's two major trading powers, giving rise to fears of a full-blown transatlantic trade war and a new wave of global protectionism. The contributors to this Forum look at the causes of, and possible remedies for, this development, taking economic, legal and political aspects into consideratio