W. Brian

activity

20232026

collaborators

4 papers

math.LO2026

Nontrivial automorphisms of $P (ω) / Fin$ in Cohen models

Will Brian, Alan Dow

We show that if $κ < ℵ_{ω}$ Cohen reals are added to a model of $CH$ , then there are nontrivial automorphisms of $P (ω) / Fin$ in the extension. Under som…

math.GN2026

A parametrized $♢$ for the Laver property and nontrivial automorphisms of $P (ω) / Fin$

Will Brian, Alan Dow

We introduce a new parametrized diamond principle denoted $♢ (LP)$ . This principle is akin to the parametrized diamonds of Moore, Hrušák, and Džamonja, each of w…

math.GN2025

$M^{}$ , $N^{}$ , and $H^{*}$

Will Brian, Alan Dow, Klaas Pieter Hart

Let $M = N \times [0, 1]$ . The natural projection $π : M \to N$ , which sends $(n, x)$ to $n$ , induces a projection mapping $π^*: \mathbb{M}^*…

math.GN2023

On Roitman's principles $MH$ and $Δ$

Hector Barriga-Acosta, Will Brian, Alan Dow

The Model Hypothesis (abbreviated $MH$ ) and $Δ$ are set-theoretic axioms introduced by J. Roitman in her work on the box product problem. Answering some questions of Roitm…

Nontrivial automorphisms of P(ω)/Fin in Cohen models

A parametrized ♢ for the Laver property and nontrivial automorphisms of P(ω)/Fin

M∗, N∗, and H∗

On Roitman's principles MH and Δ

Nontrivial automorphisms of $P (ω) / Fin$ in Cohen models

A parametrized $♢$ for the Laver property and nontrivial automorphisms of $P (ω) / Fin$

$M^{}$ , $N^{}$ , and $H^{*}$

On Roitman's principles $MH$ and $Δ$