Borel summable semiclassical expansions in 1D quantum mechanics are considered. These are the Borel summable expansions of fundamental solutions and of quantities constructed with their help. An expansion, called topological, is constructed for the corresponding Borel functions. Its main property is to order the singularity structure of the Borel plane in a hierarchical way by an increasing com...

In [10] we introduced a new notion of isomorphisms for topological measure spaces, which preserve almost sure continuity of mappings, almost sure convergence of random variables, and weak convergence of probability measures. The main thrust of that paper is the construction of an isomorphism from a Polish space with a nonatomic Borel probability measure to the unit Lebesgue interval (I, *). App...

We present several naturally defined σ–ideals which have Borel bases but, unlike for the classical examples, these bases are not of bounded Borel complexity. We investigate set-theoretic properties of such σ–ideals.

We demonstrate that a reproducing kernel Hilbert or Banach space of functions on a separable absolute Borel space or an analytic subset of a Polish space is separable if it possesses a Borel measurable feature map.

We present some applications of Popa’s Superrigidity Theorem to the theory of countable Borel equivalence relations. In particular, we show that the universal countable Borel equivalence relation E∞ is not essentially free.

In 1937, Baer [5] introduced the notion of the type of an element in a torsion-free abelian group and showed that this notion provided a complete invariant for the classification problem for torsion-free abelian groups of rank 1. Since then, despite the efforts of such mathematicians as Kurosh [23] and Malcev [25], no satisfactory system of complete invariants has been found for the torsion-fre...