6 papers
A non-trivially non-trivial automorphism at an inaccessible cardinal
Márk Poór, Jing Zhang
We show that, relative to the existence of an inaccessible cardinal, it is consistent that for an inaccessible cardinal , there is a non-trivial automorphism of $\mathcal{P}(κ)/…
Homeomorphisms of continua through projective Fraïssé limits
Márk Poór, Sławomir Solecki
We study homeomorphisms and the homeomorphism groups of compact metric spaces using the automorphism groups of projective Fraïssé limits. In our applications, we investigate the Po…
A Shelah group in ZFC
Márk Poór, Assaf Rinot
In a paper from 1980, Shelah constructed an uncountable group all of whose proper subgroups are countable. Assuming the continuum hypothesis, he constructed an uncountable group $G…
On the weak Borel chromatic number and cardinal invariants of the continuum
Márk Poór, Saharon Shelah
We prove that consistently, cov(, where denotes the weak Borel chromatic number of the…
Between Whitehead groups and uniformization
Márk Poór, Saharon Shelah
For a given stationary set of countable ordinals we prove (in ) that the assertion "every -ladder system has -uniformization" is equivalent to "every…
Universal graphs between a strong limit singular and its power
Márk Poór, Saharon Shelah
The paper settles the problem of the consistency of the existence of a single universal graph between a strong limit singular and its power. Assuming that in a model of $\mathbf{GC…