3 papers
math.LO2025
Isomorphism types of definable (maximal) cofinitary groups
Lukas Schembecker
Kastermans proved that consistently has a cofinitary representation. We present a short proof that alway…
math.LO2025
Cofinitary groups and projective well-orders
Vera Fischer, Lukas Schembecker, David Schrittesser
We introduce the notion of a tight cofinitary group, which captures forcing indestructibility of maximal cofinitary groups for a long list of partial orders, including Cohen, Sacks…
math.LO2025
Partitions of Baire space into compact sets
Vera Fischer, Lukas Schembecker
Under we construct a partition of Baire space into compact sets, which is indestructible by countably supported iteration and product of Sacks forcing of any length, an…