David Schrittesser

activity

20242026

collaborators

8 papers

math.LO2026

Loeb Equivalence for General Internal Probability Spaces

Haosui Duanmu, Xinyu Liu, David Schrittesser

Loeb measure theory stands as one of the most influential concepts in nonstandard analysis, underpinning nearly all applications in probability, stochastic processes, and mathemati…

math.FA2026

Generalized almost disjoint families and injective Banach spaces

Chris Lambie-Hanson, David Schrittesser

A fundamental open problem in the homological theory of Banach spaces is the calculation of the injective dimension of the Banach space $c_{0}$ . We make a contribution to the study o…

math.LO2025

Definable discrete sets with large continuum

David Schrittesser

Let $R$ be a $I^£_{1}^{1}$ binary relation and call a set $R$ -discrete iff no two distinct of its elements are $R$ -related. We show that in the extension of $…

math.LO2025

The happy coexistence of mad families and Laver measurability

Asger Tornquist, David Schrittesser

Let $x$ denote a Laver real over $L$ . We prove that in $L [x]$ there is a $I^_{1}^{1}$ infinite mad family. Since $I^_{1}^{1}$ and $I^£_{2}^{1}$ sets are Laver measurable in $L [x]$ , this shows t…

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

Good projective witnesses

Vera Fischer, Sy David Friedman, David Schrittesser +1

We develop a new forcing notion for adjoining self-coding cofinitary permutations and use it to show that consistently, the minimal cardinality $a_{g}$ of a maxima…