6 papers
Trace-norm rigidity for reduced products of unitary groups and matrix algebras
Ben De Bondt, Andreas Thom
We study homomorphisms, with a focus on isomorphisms, between the tracial metric reduced products of finite dimensional unitary groups and of matrix algebras. A variant of Ulam sta…
Adding cofinal countable sequences through multiple regular cardinals by ssp forcing
Ben De Bondt, Boban Velickovic
We present a direct construction of stationary set preserving forcings that make -cofinal all the members of some arbitrary set of regular cardinals . In a…
On automorphism groups of metric reduced products of symmetric groups
Ben De Bondt, Andreas Thom
We study isomorphisms between metric reduced products of symmetric groups with the normalized Hamming metric assuming the open coloring axiom and Martin's axiom for…
A metric lifting theorem
Ben De Bondt, Alessandro Vignati
In a recent article by Farah and the authors, a strong lifting theorem was proved for a class of coordinate-respecting maps between reduced products of discrete structures, hereby…
Increasing the second uniform indiscernible by strongly ssp forcing
Ben De Bondt, Boban Velickovic
We introduce a new and natural stationary set preserving forcing that (under precipitous + existence of $H_θ^#$ for a sufficiently large…
Games on AF-algebras
Ben De Bondt, Andrea Vaccaro, Boban Velickovic +1
We analyze -algebras, particularly AF-algebras, and their -groups in the context of the infinitary logic . Given two separable unital AF-…