Silvan Horvath

collaborators

3 papers

math.LO2026

On the number of $Q$ -points

Silvan Horvath, Tan Özalp

We show that, up to isomorphism, the number of $Q$ -points is either finite, $2^{d}$ or $2^{c}$ . This answers a question asked by Borodulin-Nadzieja, Martínez-…

math.LO2026

A unique $Q$ -point and infinitely many near-coherence classes of ultrafilters

Lorenz Halbeisen, Silvan Horvath, Saharon Shelah

We show that in the model obtained by iteratively pseudo-intersecting a Ramsey ultrafilter via a length- $I ¨ _{2}$ countable support iteration of restricted Mathias forcing over a grou…

math.LO2025

There may be exactly $n$ $Q$ -points

Lorenz Halbeisen, Silvan Horvath, Tan Ãzalp

We generalize the main result of arXiv:2505.17960 and show the consistency of the statement ``There are exactly $n$ $Q$ -points up to isomorphism" for any finite $n$ . Furthermore, w…

On the number of Q-points

A unique Q-point and infinitely many near-coherence classes of ultrafilters

There may be exactly n Q-points

On the number of $Q$ -points

A unique $Q$ -point and infinitely many near-coherence classes of ultrafilters

There may be exactly $n$ $Q$ -points