collaborators

7 papers

math.LO2026

The class and dynamics of -balanced Polish groups

Shaun Allison, Aristotelis Panagiotopoulos

For each ordinal , we introduce the class of -balanced Polish groups. These classes form a hierarchy that completely stratifies the space between the class of Polish g…

math.LO2024

The definable content of homological invariants I: &

Jeffrey Bergfalk, Martino Lupini, Aristotelis Panagiotopoulos

This is the first installment in a series of papers in which we illustrate how classical invariants of homological algebra and algebraic topology can be enriched with additional de…

math.LO2024

Quasi-invariant measures concentrating on countable structures

Clinton Conley, Colin Jahel, Aristotelis Panagiotopoulos

Countable -structures whose isomorphism class supports a permutation invariant probability measure in the logic action have been characterized by Ackerma…

math.LO2024

The definable content of homological invariants II: Čech cohomology and homotopy classification

Jeffrey Bergfalk, Martino Lupini, Aristotelis Panagiotopoulos

This is the second installment in a series of papers applying descriptive set theoretic techniques to both analyze and enrich classical functors from homological algebra and algebr…

math.AT2024

Definable (co)homology, pro-torus rigidity, and (co)homological classification

Jeffrey Bergfalk, Martino Lupini, Aristotelis Panagiotopoulos

We show that the classical homology theory of Steenrod may be enriched with descriptive set-theoretic information. We prove that the resulting definable homology theory provides a…

math.LO2024

Strong ergodicity phenomena for Bernoulli shifts of bounded algebraic dimension

Aristotelis Panagiotopoulos, Assaf Shani

The algebraic dimension of a Polish permutation group is the smallest , so that for all of size , the orbit of…