Research interests: Holomorphic Dynamics, Renormalization, Resurgence Theory, Computability and Computational Complexity in Dynamics

Representations of infinite-dimensional groups, Groups acting on rooted trees, Self-similar groups, Spectral Theory, Ergodic Theory

Recent and future events:

Simons Semester "Continued Fractions, Fractals, and Dynamics", April 27-May 31, 2026, Będlewo and Warsaw, Poland
Simons Semester "Invariant structures in groups, spaces, and algebras", January 12-February 15, 2026, Będlewo and Warsaw, Poland

Dynamical Systems Seminar at IM PAN

ICMU on-line minicourses

Conference "On geometric complexity of Julia sets VI", August 3-8, 2025, Będlewo, Poland
Conference "Ergodic group actions and unitary representations II", June 15-19, 2025, Będlewo, Poland
Conference "On geometric complexity of Julia sets V", July 21-26, 2024, Będlewo, Poland
Conference "Ergodic group actions and unitary representations", June 16-20, 2024, Warsaw, Poland
IM PAN Dynamical Systems Seminar

Invited talks:

October 24, 2025, On spectra of self-similar groups and graphs, Spectral Theory Seminar at University of Ljubljana, Slovenia

September 11, 2025, Characters on infinite discrete groups and their applications, 10th Forum of Polish Mathematicians, University of Bialystok, Poland

October 16, 2024, Characters and factor representations of infinite discrete groups: methods and phenomena, Group actions and representations together with Random Matrix Theory, Warsaw, Poland

October 9, 2024, On spectra of self-similar groups and graphs, IM PAN Colloquium, Warsaw, Poland

May 13, 2024, On spectral measures of self-similar graphs, Groups and Graphs Seminar, Budapest, Hungary

March 21, 2023, On spectral properties of the Schreier graphs of the Thompson group F, Groups of Dynamical Origins, Automata and Spectra, Les Diablerets, Switzerland

November 28, 2022, From invariant ergodic measures to indecomposable characters on full groups, Group Actions: Dynamics, Measure, Topology University of Munster, Germany

October 25, 2022, On Hausdorff dimension of Julia sets via a computer-assisted proof, Dynamics Seminar, IST Austria

May 31, 2022, New estimates from below on the Hausdorff dimension of some Julia sets, Workshop in Dynamics, Uppsala University, Sweden

June 16, 2021, On Hausdorff dimension of Julia sets of real Feigenbaum maps, Conference "The 9th Visegrad Conference, Dynamical Systems", Prague, Czech Republic (on-line)

May 13, 2019, On computational complexity of Julia sets, Mathematics Colloquium at Jacobs University, Bremen, Germany.

January 28, 2019, Can one hear the shape of a group?, Alfred Renyi Institute of Mathematics, Budapest, Hungary.

January 17, 2019, On computational complexity of Cremer Julia sets, Ergodic Theory and Dynamical Systems Seminar, University of Warwick, Coventy, UK.

January 15, 2019, On Hausdorff dimension of the Feigenbaum Julia set, Dynamical Systems Seminar, Imperial College London, UK.

July 23, 2018, On Hausdorff dimension of the Feigenbaum Julia set, Dynamical Systems Seminar, University of Barcelona, Spain.

July 5, 2018, On computability and computational complexity of Julia sets, Workshop "New Developments in Complex Analysis and Function Theory", University of Crete, Heraklion, Greece.

March 27, 2018, On the Lebesgue measure of the Feigenbaum Julia set, Workshop "Algorithmic Questions in Dynamical Systems", Institut de Mathématiques de Toulouse, France.

August 14, 2017, On the Julia set of the Feigenbaum quadratic polynomial, Conference "Just a little calculation in dynamics", Bedlewo, Poland.

April 5, 2016, On computational aspects of the Feigenbaum fixed point of period-doubling renormalization,  Workshop "Computation in Dynamics", ICERM, Brown University, USA.

March 20, 2016, On measure of the Feigenbaum fixed point Julia set,  AMS special session "Holomorphic Dynamics", Spring Eastern Sectional Meeting, Stony Brook University, USA.

February 26, 2016, On spectra of Koopman, groupoid and quasi-regular representations, New York Applied Algebra Collogquium, CUNY Graduate Center, USA.

November 12, 2015, On Koopman, groupoid and quasi-regular representations and weakly branch groups, Conference "Geometric and Probabilistic Methods in Group Theory and Dynamical Systems", Texas A&M University, USA.

September 12, 2014, On diagonal actions of branch groups and the corresponding characters, Linear Analysis Seminar, Texas A&M University, USA.

September 10, 2014, Representations associated with group actions and spectra of Hecke type operators, Groups and Dynamics Seminar, Texas A&M University, USA.  

February  25, 2014, On characters of approximately finite groups and Higman-Thompson groups, Conference "Groups acting on rooted trees and around", Paris, France.

December 8, 2013, The Julia set of the Feigenbaum map is poly-time computable, Section "Holomorphic dynamics and related topics", CMS Winter meeting, Ottawa, Canada.

October 17, 2013, On the resurgent approach to local dynamics of simple parabolic germs, Workshop "Topological and Combinatorial Problems in One-dimensional Complex Dynamics", Pisa, Italy.

January 21, 2013, Dynamics of parabolic germs via Resurgence Theory, Dynamical Systems Seminar, University of Toronto, Canada.

February 16, 2012, Computability of Julia sets: a survey, Ergodic Theory and Probability Seminar, The Ohio State University, USA.

September 9, 2011, On characters of inductive limits of symmetric groups, Workshop on Symmetric Functions and its Applications, City University of New York, USA.

May 4, 2011, Ecalle-Voronin invariants and resurgent functions, Dynamical Systems Seminar, Centro di Ricerca Matematica Ennio de Giorgi, Pisa, Italy.