4 papers
Minimal Banach-Tarski decompositions
Cesare Straffelini, Kilian Zambanini
We investigate the problem of finding the minimum number of pieces necessary for dividing a three-dimensional sphere or a ball and reassembling it to form congruent copies of t…
Terminal Absoluteness of Collapse Forcings
Cesare Straffelini
Generic absoluteness is the phenomenon that certain truths in the set-theoretic universe remain stable under forcing expansions. A classical result by Kripke asserts that every com…
Higher Solovay Models
Cesare Straffelini, Sebastiano Thei
We introduce an axiomatisation of when a model of the form can be considered a ``-Solovay model''; we show a characterisation of -Solovay models; and we pro…
Simultaneous Sequential Compactness
Sirio Resteghini, Cesare Straffelini
A set of sequences is said to converge simultaneously if there exists an infinite subset of the index set such that all sequences converge when restricted to . We discu…