4 papers
Isometry groups of Polish ultrametric spaces
Riccardo Camerlo, Alberto Marcone, Luca Motto Ros
We solve a long-standing open problem, formulated by Krasner in the 1950's, in the context of Polish (i.e. separable complete) ultrametric spaces by providing a characterization of…
Generalized Descriptive Set Theory at Singular Cardinals of Countable Cofinality
Vincenzo Dimonte, Luca Motto Ros
We provide a comprehensive development of the basics of descriptive set theory for non-separable complete metric spaces whose weight is a singular cardinal of countable confin…
Generalized Borel Sets
Claudio Agostini, Nick Chapman, Luca Motto Ros +1
Generalizing classical descriptive set theory opens foundational questions about the Borel hierarchy. In this paper we systematically study those questions, working in the general…
Structural results on idealistic equivalence relations
Filippo Calderoni, Luca Motto Ros
We address some fundamental problems concerning the structure of idealistic equivalence relations. In particular, we show that, under analytic determinacy, there are continuum many…