Toshimichi Usuba

activity

20132025

most citedChoiceless Löwenheim-Skolem property and uniform definability of grounds

1 citations · 3 across the 15 of their papers we have counts for

collaborators

Showing 2018Show all

2 papers · 1 filter

math.LO2018

Products of Lindelöf spaces with points $G_{δ}$

Toshimichi Usuba

We show that if CH holds and either (i) there exists an $ω_{1}$ -Kurepa tree, or (ii) $□ (ω_{2})$ holds, then there are regular $T_{1}$ Lindelöf spaces $X_{0}$ and $X_{1}$ with points $G…

math.LO2018

Extendible cardinals and the mantle

Toshimichi Usuba

The mantle is the intersection of all ground models of $V$ . We show that if there exists an extendible cardinal then the mantle is a ground model of $V$ .

Products of Lindelöf spaces with points Gδ​

Extendible cardinals and the mantle

Products of Lindelöf spaces with points $G_{δ}$