activity
20112026
most citedOn Polish groups admitting non-essentially countable actions

7 citations · 15 across the 19 of their papers we have counts for

collaborators

27 papers

math.DS2026

Rokhlin properties in homeomorphism groups of compact metric spaces

Maciej Malicki

We develop a general framework for studying generic homeomorphisms of compact metric spaces using combinatorial amalgamation methods inspired by Fraïssé theory. Our approach combin…

math.LO2026

Universal homogeneous two-sorted ultrametric spaces

Adam Bartoš, Wiesław Kubiś, Aleksandra Kwiatkowska +1

We view ultrametric spaces as two-sorted structures consisting of a set of points and of a linearly ordered set of distances. We call the appropriate notion of embeddings distance-…

math.LO2026

Generic dc-automorphisms of two-sorted ultrametric spaces

Adam Bartoš, Wiesław Kubiś, Aleksandra Kwiatkowska +1

We continue to study ultrametric spaces as two-sorted structures consisting of a set of points and of a linearly ordered set of distances, together with the dc-embeddings, which we…

math.LO2025

A logic of co-valuations

Maciej Malicki

A co-valuation is, essentially, a minimal finite cover. We introduce a logic based on co-valuations, which play the role of valuations of free variables in classical first-order lo…

math.LO2025

Isomorphism of almost locally compact Polish metric structures

Maciej Malicki

A topological space is almost locally compact if it contains a dense locally compact subspace. We generalize a result from \cite{Ma}, showing that isomorphism on Borel classes of a…

math.LO2025

Automorphism groups of measures on the Cantor space. Part I: Good measures and Rokhlin properties

Michal Doucha, Dominik Kwietniak, Maciej Malicki +1

We study criteria for the existence of a dense or comeager conjugacy class in the automorphism group of a given measure on the Cantor space. We concentrate on good measures, define…

math.LO2025

The rational Gurarii space and its linear isometry group

Ondřej Kurka, Maciej Malicki

We show that the classes of partial isometries in finite-dimensional polyhedral spaces and in finite-dimensional rational polyhedral spaces do not have the weak amalgamation proper…

math.GN2024

Homeomorphisms of the Pseudoarc

Tristan Bice, Maciej Malicki

We construct homeomorphisms of compacta from relations between finite graphs representing their open covers. Applied to the pseudoarc, this yields simple Fraïssé theoretic proofs o…

math.LO2022

Isomorphism of locally compact Polish metric structures

Maciej Malicki

We study the isomorphism relation on Borel classes of locally compact Polish metric structures. We prove that isomorphism on such classes is always classifiable by countable struct…

math.LO2021

Continuous logic and Borel equivalence relations

Andreas Hallbäck, Maciej Malicki, Todor Tsankov

We study the complexity of isomorphism of classes of metric structures using methods from infinitary continuous logic. For Borel classes of locally compact structures, we prove tha…

math.LO2019★ 7 cited

On Polish groups admitting non-essentially countable actions

Alexander S. Kechris, Maciej Malicki, Aristotelis Panagiotopoulos +1

It is a long-standing open question whether every Polish group that is not locally compact admits a Borel action on a standard Borel space whose associated orbit equivalence relati…

math.LO2019

Remarks on weak amalgamation and large conjugacy classes in non-archimedean groups

Maciej Malicki

We study the notion of weak amalgamation in the context of diagonal conjugacy classes. Generalizing results of Kechris and Rosendal, we prove that for every countable structure …

math.LO2019

Ordered structures and large conjugacy classes

Aleksandra Kwiatkowska, Maciej Malicki

This article is a contribution to the following problem: does there exist a Polish non-archimedean group (equivalently: automorphism group of a Fraisse limit) that is extremely ame…

math.LO2018

Topologically 2-generated groups

Aleksandra Kwiatkowska, Maciej Malicki

We prove that for a number of ultrahomogeneous structures , including those with the free amalgamation property, the powers of the automorphism group , $n=1,2,\…

math.GR2017

Property (T), finite-dimensional representations, and generic representations

Michal Doucha, Maciej Malicki, Alain Valette

Let be a discrete group with property (T). It is a standard fact that, in a unitary representation of on a Hilbert space , almost invariant vectors are close t…

math.GR2017

Generic representations of countable groups

Michal Doucha, Maciej Malicki

The paper is devoted to a study of generic representations (homomorphisms) of discrete countable groups in Polish groups , i.e. those elements in the Polish space $\mathrm{R…

math.LO2016

Automorphism groups of countable structures and groups of measurable functions

Aleksandra Kwiatkowska, Maciej Malicki

Let be a topological group and let be the Lebesgue measure on the interval . We let to be the topological group of all -equivalence classes of -measur…

math.GR2015

An example of a non non-archimedean Polish group with ample generics

Maciej Malicki

For an analytic -ideal , is the Polish group of all the permutations of whose support is in , with Polish topology given by the corresponding submeasure…

math.LO2014★ 4 cited

Matheme and mathematics. On the main concepts of the philosophy of Alain Badiou

Maciej Malicki

In this paper, I present a critical discussion of mathematical arguments employed in the philosophy of event of Alain Badiou. On the basis of "Being and Event" as well as his other…

math.LO2014

Abelian pro-countable groups and non-Borel orbit equivalence relations

Maciej Malicki

We study topological groups that can be defined as Polish, pro-countable abelian groups, as non-archimedean abelian groups or as quasi-countable abelian groups, i.e., Polish subdir…

math.LO2014

Consequences of the existence of ample generics and automorphism groups of homogeneous metric structures

Maciej Malicki

We define a simple criterion for a homogeneous, complete metric structure that implies that the automorphism group $\mbox{Aut}(X)$ satisfies all the main consequences of the ex…

math.GR2014

Abelian pro-countable groups and orbit equivalence relations

Maciej Malicki

We study groups that can be defined as Polish, pro-countable groups, as non-archimedean groups with an invariant metric or as quasi-countable groups, i.e., closed subdirect product…

math.GR2013

Generic elements in isometry groups of Polish ultrametric spaces

Maciej Malicki

This paper presents a study of generic elements in full isometry groups of Polish ultrametric spaces. We obtain a complete characterization of Polish ultrametric spaces X whose iso…

math.DS2013

Cooperative Boolean systems with generically long attractors II

Winfried Just, Maciej Malicki

We prove that cooperativity in Boolean networks precludes a strong notion of sensitive dependence on initial conditions. Weaker notions of sensitive dependence are shown to be cons…