5 papers · 1 filter
Hagendorf Orders
Jonathan Schilhan, Thilo Weinert
Call a linear order type Hagendorf if it shares two properties with additively indecomposable ordinal numbers without being one itself: is strictly indecomposable to the ri…
Infinite-Exponent Partition Relations on Higher Analogues of the Real Line
Lyra A. Gardiner, Jonathan Schilhan, Thilo Weinert
We present a number of results concerning infinite-exponent partition relations on linear orders of the form for an ordinal, generalising…
Wetzel families and the continuum
Jonathan Schilhan, Thilo Weinert
We provide answers to a question brought up by Erdős about the construction of Wetzel families in the absence of the continuum hypothesis - a Wetzel family is a family $\mathcal{F}…
Tree forcing and definable maximal independent sets in hypergraphs
Jonathan Schilhan
We show that after forcing with a countable support iteration or a finite product of Sacks or splitting forcing over , every analytic hypergraph on a Polish space admits a $\mat…
Coanalytic Ultrafilter Bases
Jonathan Schilhan
We study the definability of ultrafilter bases on in the sense of descriptive set theory. As a main result we show that there is no coanalytic base for a Ramsey ultrafilter, wh…