Michael P. Cohen

activity

20172020

most citedA Kuratowski closure-complement variant whose solution is independent of ZF

1 citations · 1 across the 1 of their papers we have counts for

collaborators

3 papers

math.GN2020★ 1 cited

A Kuratowski closure-complement variant whose solution is independent of ZF

Michael P. Cohen, Todd Johnson, Adam Kral +2

We pose the following new variant of the Kuratowski closure-complement problem: How many distinct sets may be obtained by starting with a set $A$ of a Polish space $X$ , and applyin…

math.GR2019

Maximal pseudometrics and distortion of circle diffeomorphisms

Michael P. Cohen

We initiate a study of distortion elements in the Polish groups $\mbox{Diff}_+^k(\mathbb{S}^1)$ ( $1 \leq k < \infty$ ), as well as $\mbox{Diff}_+^{1+AC}(\mathbb{S}^1)$, in terms of max…

math.GR2017

Polishability of some groups of interval and circle diffeomorphisms

Michael P. Cohen

Let $M = I$ or $M = S^{1}$ and let $k \geq 1$ . We exhibit a new infinite class of Polish groups by showing that each group $Diff_{+}^{k + A C} (M)$ , consisting of those $C…