Jan Greb'ik

collaborators

5 papers

math.LO2020

Tall $F_{σ}$ subideals of tall analytic ideals

Jan Grebík, Zoltán Vidnyánszky

Answering a question of Hrušák, we show that every analytic tall ideal on $ω$ contains an $F_{σ}$ tall ideal. We also give an example of an $F_{σ}$ tall ideal without a Borel selector.

math.LO2020

Scrambled Cantor sets

Stefan Geschke, Jan Grebík, Benjamin D. Miller

We show that Li-Yorke chaos ensures the existence of a scrambled Cantor set.

math.CO2019

Measurable versions of Vizing's theorem

Jan Grebík, Oleg Pikhurko

We establish two versions of Vizing's theorem for Borel multi-graphs whose vertex degrees and edge multiplicities are uniformly bounded by respectively $Δ$ and $π$ . The ``approxima…

math.LO2017

No minimal tall Borel ideal in the Katětov order

Jan Grebík, Michael Hrušák

Answering a question of the second listed author we show that there is no tall Borel ideal minimal among all tall Borel ideals in the Katětov order.

math.GN2016

The Ascoli property for function spaces

Saak Gabriyelyan, Jan Grebík, Jerzy Kakol +1

The paper deals with Ascoli spaces $C_{p} (X)$ and $C_{k} (X)$ over Tychonoff spaces $X$ . The class of Ascoli spaces $X$ , i.e. spaces $X$ for which any compact subset $K$ of $C_{k} (X)$ is…