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The Budapest - Wien Dynamics seminar

 This is a series of seminars initiated to foster exchange between the
 very dynamical ergodic theory groups based in Vienna and Budapest. 

Organizers: Henk Bruin, Peter Balint

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Upcoming events:

• 29 January 2021 , online, via ZOOM.
  
  Another afternoon of jolly good talks about this and that.
  
  
  •    14:00 - 15:00:  Jorge Milhazes Freitas (University of Porto):  
    Enhanced functional limit theorems for chaotic dynamics and heavy tailed observables. 
    
       Abstract:  

    We consider stochastic processes arising from chaotic systems by evaluating an heavy tailed 
    observable function along the orbits of the system. We prove the convergence of a normalised 
    sum process to a LĂŠvy process with excursions, designed to describe the oscillations 
    observed during the clusters of extremal observations. The applications to specific systems 
    include both hyperbolic and non-uniformly expanding systems.

    
    
    
    
  •    15:15 - 16:15:  Balázs Bárány (TU Budapest):  
    On the Ahlfors regularity of planar self-affine sets.
    
        Abstract:   

    In this talk, we study the Ahlfors regularity of planar self-affine sets under natural 
    conditions: strong separation condition, strong irreducibility and proximality. Not 
    surprisingly, if the dimension is strictly larger than 1, the set is never Ahlfors regular. 
    In case if the dimension is less than or equal to 1 under the extra condition of dominated 
    splitting, we show that the Ahlfors regularity is equivalent to the positive proper 
    dimensional Hausdorff measure and to positive proper dimensional Hausdorff measure of the 
    projections in every Furstenberg direction. Moreover, we introduce a condition called 
    "projective separation", which is equivalent to having positive measure, and which is 
    applicable to show that both positive and zero Hausdorff measure happens on reasonably 
    large sets of translation parameters. This is a joint work with Antti Käenmäki and Han Yu.

    
    
    
    
  •    16:30 - 17:30:  Itzhak Fouxon (Yonsei University, Seoul & Ben-Gurion University, Beer Sheva):   
    Effect of emergent distinguishability of particles in a non-equilibrium chaotic system.
    
       Abstract:   

    We consider the behavior of classical particles which evolution consists of free motion 
    interrupted by binary collisions. The fluid of hard balls and the dilute gas with 
    arbitrary short-range interactions are treated, where the total number of particles is 
    moderate (say, five particles). We show that the numbers of collisions of a given particle 
    with other particles grow effectively as a biased random walk. This is used to prove that 
    over indefinitely long periods of time each particle has preferences: it systematically 
    collides more with certain particles and less with others. This property originates in the 
    arcsine law.Thus certain particles are effectively attracted and certain others are repelled, 
    making the particles effectively distinguishable. The effect is of statistical origin and it 
    reminds of entropic forces.

  
  
  
     The link for the zoom meeting will be sent out to the BudWiSer list.
     To register, send a message to budwiser.dynamics AT gmail.com 
  
  
  
  
  

Projected events:   Tentative dates for subsequent meetings:  March 2021,  ... , 

Past events:

• 4 December 2020, online, via ZOOM.
  
  
  
  • Peter Varju (University of Cambridge):  On the dimension of self-similar measures. 
    
    
  • Martin Leguil (Universite de Picardie):  Spectral rigidity of hyperbolic billiards.
    
    
  • Vadim Kaloshin (University of Maryland):   Marked length spectral determination of analytic strictly convex domains.
    
    

• 25 September 2020 , online, via ZOOM:
  This seminar was dedicated to the 85th birthday of Yakov Sinai.
  
  
  
  • Balint Toth (Bristol & Budapest):  Invariance principle for the Random Lorentz Gas - Beyond the Boltzmann-Grad Limit. 
    
    
  • Françoise Pène (Brest):  Limit theorems for unbounded observables via operator perturbation techniques. (slides)
    
  • Peter Nandori (Yeshiva University):  Flexibility of ergodic properties and the central limit theorem in smooth systems. (slides)  
    
    

• 13 March 2020 , University of Vienna:
  
  • Viviane Baladi (Paris):  On the measure of maximal entropy of Sinai billiards. 
    
    
  • Imre Peter Toth (Budapest): Non-integrability in circular billiards.
    
  • Tomas Persson (Lund):  Recurrence.   
    
  
  

• 31 Jan 2020 , Budapest University of Technology and Economics (local information here):
  
  
  • Karoly Simon (BME Budapest):  Appropriate dimensional Hausdorff measure of typical self-similar and self-conformal attractors on the line.
    
    
  • Zoltan Buczolich (Budapest): Fast and slow points of Birkhoff sums.
    
    
    
  • Olli Hella (Helsinki): Stein's method for dynamical systems.
    

• 8 Nov 2019 , Budapest University of Technology and Economics (local information here):
  
  
  • Balazs Barany  (Budapest):  Superexponential condensation without exact overlaps.
    
    
  • Dalia Terhesiu (Leiden): Rates of mixing for the Lorenz gas.
    
    
    
  • Maik Gröger   (U Vienna): Bifurcation sets from families of bounded orbits, open dynamics and matching.
    

• 27 Sept 2019 , University of Vienna:
  
  
  • Toru Sera (Kyoto): A conditional limit theorem for the Pomeau-Manneville map.
    
    
  • Tanja Schindler (Australian National University, SNS Pisa): 
       Strong laws under trimming - a comparison between iid random variables and dynamical systems.
    
    
    
  • Jon Aaronson (Tel Aviv):  On mixing of infinite measure preserving transformations.
    
    
  
  

• 3 May 2019, Budapest University of Technology and Economics (local information here):
  
  
  • Mike Todd (U of St.Andrews): Escape rates for multimodal maps with holes. 
    
    
  • Nandor Simanyi (Birmingham, AL): Asymptotic homotopic complexity of 2D dispersing billiards.
    
    
  • Domokos Szasz (Budapest): Andras Kramli (1943-2019).
    
    
  
  

• 5 April 2019, University of Vienna:
  
  • Abel Farkas (Renyi Institute):  Interval projections of self-similar sets. 
    
    
  • Peter Balint (BME Budapest):  Marked length spectrum and the geometry of open dispersing billiards.
    
    
  • Maja Resman (U Zagreb):   Formal classification of power-logarithmic germs and fractal approach.
    
    
    

• 1 March 2019, Budapest University of Technology and Economics (local information here):
  
  
  • Karoly Simon   (BME Budapest):    Hausdorff dimension for som non-Markovian repellers.
    
    
  • Maik Gröger   (U Vienna):    Amorphic complexity, substitution subshifts and iterated function systems.
    
    
  • Henk Bruin (U Vienna): Limit laws for almost Anosov flows.
  
  

• 25 January 2019, University of Vienna:
  
  
  • Karoly Simon   (BME Budapest):    Hausdorff dimension of some non-conformal attractors.
    
    
  • Sascha Troscheit  (U Vienna):   Self-conformal sets with positive Hausdorff measure.
    
    
  • Benjamin Vejnar   (Prague):    Complexity of the homeomorphism relation between compact spaces.
  
  

• 9 November 2018, Budapest University of Technology and Economics (local information here):
  
  
  • Michal Rams  (Impan Warsaw): Badly approximable numbers for irraional rotation. 
    
    
  • Feliks Przytycki  (Impan Warsaw): Geometric coding trees for iterations of rational maps.
    
    
  • Alejandro Kocsard  (Univ Federal Fluminense):  The Burnside problem for groups of diffeomorphisms.
  
  

• 20 September 2018, University of Vienna:
  
  
  • Dalia Terhesiu (Exeter):   Mixing for some Z-extensions of suspension flows. 
    
    
  • Balazs Barany (Budapest):  Dimension of planar self-affine measures with application to Birkhoff and Lyapunov spectra.
    
    
  • Gabriel Fuhrmann (Imperial College):  Unique ergodicity and zero entropy of irregular symbolic extensions of irrational rotations.
    
  
  

• 27 April 2018, Budapest University of Technology and Economics (local information here):
  
  
  • Karoly Simon (BME Budapest):  Hausdorff dimnsion for triangular self-affine IFS.
    
    
  • Alexey Korepanov (Exeter):  Strength of strong approximation with a Brownian motion.
    
    
  • Thomas Gilbert (Brussels):  The stochastic Lotka-Volterra predator-prey model: it keeps cycling on!
    
  
  

• 2 March 2018, University of Vienna:
  
  
  • Manos Zafeiropoulos (Graz):  Inhomogeneous Diophantine Approximation on M_0 sets.
    
    
  • Balazs Barany (Budapest):  Almost multiplicativity of planar matrix cocycles and the difference between quasi-Bernoulli and Gibbs measures.
    
    
  • Benoit Kloeckner (Paris Est):  Optimal transportation, transfer operators and decay of correlations. 
    
    

• 20 Dec 2017, Budapest University of Technology and Economics (local information here):
  
  
  • Fanni Selley (BME Budapest): Stability of the invariant distribution in infinite systems of coupled maps.
    
    
  • Françoise Pène (Brest):  Stochastic properties of the Z² periodic Sinai billiard.
    
    
  • Benoit Saussol (Brest):  Spatio-temporal Poisson process for visits to small sets in hyperbolic dynamics.

• 20 Oct 2017,  University of Vienna:
  
  
  • Jun Luo (Chongqing University):  Lipschitz equivalence of self-similar fractals.
    
    
  • Michal Rams (Warsaw):  Lyapunov spectra of matrix cocycles.
    
    
  • Nandor Simanyi (Birmingham, AL):  Noncommutative Rotation Vectors for Certain Cylindrical Billiards.

• 30 June 2017,  Budapest University of Technology and Economics (local information here):
  
  
  • Peter Kevei (University od Szeged): On the tail of the solution of random fixed point equations.
    
    
  • Henk Bruin (U Vienna): Regular variation for almost Anosov diffeomorphism.
    
    
  • Mike Todd (U of St.Andrews):  Analysis of a transient interval map.

• 28 April 2017,  University of Vienna:
  
  
  • Sonja Stimac (University of Zagreb):  Lozi-like maps.
    
    
  • Fanni Selley (BME Budapest):  Coupled map systems with a continuum of sites. 
    
    
  • Stefano Marmi (SNS Pisa):  Small divisors and interval exchange maps.

• 3 Mar 2017,  Budapest University of Technology and Economics (local information here):
  
  
  • Karoly Simon (BME Budapest):  Singularity of self-similar measures.
    
    
  • Thomas Jordan (Bristol):  Self-affine sets and Assouad dimension.
    
    
  • Vadim Kaloshin (Maryland & ETH):  Birkhoff conjecture for convex planar billiards
                                                              and deformational spectral rigidity of planar domains.

• 26 Jan 2017,  University of Vienna:
  
  
  • Jiri Cerny (U Vienna):  Maximum of Branching Random Walk in Random Environment.
    
    
  • Imre Peter Toth (Budapest):  Rare interaction limit and the evolution of unstable
                                                manifolds in a deterministic heat conduction model.
  
  

• 9 Dec 2016,  University of Vienna:
  
  • Henk Bruin (U Vienna):  Return time statistics: varying limits.
    
    
  • Peter Balint (BME Budapest):  Improved upper bound on the rate of mixing for the map of two falling balls.
    
    

•   28 Oct 2016, Budapest University of Technology and Economics:
  
  
  • Karoly Simon (Budapest):  Hausdorff dimension of certain self-affine attractors.
    
    
  • Michal Rams (Warsaw):  Inhomogneous Diophantine Approximations.
    
    
  • Roland Zweimüller (Vienna):  Poisson limits for rare events in probability preserving systems.
    
    

• 8 Apr 2016, ESI Vienna, part of thematic programme
  
  
  • Maciej Wojtkowski (Opole): Integrable and chaotic Gaussian thermostats on some homogeneous spaces.
    
    
  • Jozef Bobok (Prague):  (Quasi)similarity of polygonal billiards.
    
    
  • Balazs Barany (Budapest):  Ledrappier-Young formula and exact dimensionality of self-affine measures.
    
    
•  26 Feb 2016, Budapest University of Technology and Economics:
  
  
  • Zoltan Buczolich (Budapest): Convergence of ergodic averages for many group rotations.
    
    
  • Henk Bruin (Vienna): Sharp mixing rates via inducing w.r.t. general return times.
    
    

• 4 Dec 2015, Budapest University of Technology and Economics:
  
  
  • Alexey Korepanov (Warwick):
    Linear response for intermittent maps with summable and nonsummable decay of correlations.
    
    
  • Roland Zweimüller (Vienna): Functional stable and related limit theorems for (some) dynamical systems.
    
    
  • Imre Peter Toth  (Budapest): Equidistribution for singular measures in planar dispersing billiard flows.
    
  
  

• 2 Oct 2015, ESI Vienna, final day of workshop:
  
  An afternoon of jolly good talks about this and that, plus an even better evening!
  
  
  • Feliks Przytycki (IMPAN, Warsaw): 
    Geometric pressure in real and complex 1d dynamics via trees of pre-images and via spanning sets.
    
    
  • Fanni Selley (BME Budapest):  Mean field coupling of identical expanding circle maps. 
    
    
  • Mariusz Urbanski (Univ of Texas at Denton):  Random dynamics of transcendental meromorphic functions.
    

• 29 May 2015, University of Vienna:
  
  
  • Andras Nemedy Varga (Budapest): The flow of two falling balls mixes rapidly.
    
    
  • Simon Rechberger (Vienna):  On the relation of return- and hitting time limits in infinite ergodic systems.
    
    
  • Ian Morris (Surrey): The transfer operator for the binary Euclidean algorithm.
    
    
    

• 24 April 2015, Budapest University of Technology and Economics:
  
  
  • Zemer Kosloff (Warwick): Conservative Anosov maps on the 2-torus without absolutely continuous invariant measures.
    
    
  • Thomas Gilbert (Brussels):  Multi-state Lévy walks to describe the kinetics of diffusive processes combining ballistic motion.
    
    
  • Vadim Kaimanovich (Ottawa):  Stopping times and Poisson boundaries.
    
    
    

• 27 March 2015, University of Vienna:
  
  
  • Michael Tsiflakos (Vienna):  N falling balls are globally ergodic.
    
    
  • Lajos Vágó  (Budapest):   A parametrized family of refinement
    equations and applications to projections of generalized fractal percolations.
    
    
  • Viviane Baladi (DMA ENS Paris): The spectrum of Sinai billiard flows.
    
    

•   27 Feb 2015, Budapest University of Technology and Economics:
  
  
  • Atahualpa S. Kraemer (Düsseldorf): On the free path lengths distribution for quasiperiodic Lorentz gases.
    
    
  • Mike Todd (St Andrews): Dynamical systems with holes: slow mixing cases.
    
    
  • Stefano Luzzatto (ICTP Trieste):  SRB measures for partially hyperbolic systems whose central direction is weakly expanding.
    
    

•   12 Dec 2014, University of Vienna:
  
  
  • Henk Bruin (Vienna):  A renewal scheme for non-uniformly hyperbolic semiflows II.
                                     On tail estimates of cropped transfer operators.
    
    
  • Istvan Berkes (Graz):  Irrational rotations, GCD sums and the Khinchin conjecture.
    
    
  • Benoit Saussol (Brest):  Exponential law for random subshifts of finite type.
    
    
    
• 14 Nov 2014, Budapest University of Technology and Economics:
  
  
  • István Kolossváry (Budapest): On the local Hölder exponents of deRham-like fractal curves.
    
    
  • Françoise Pène (Brest):  Asymptotic poissonity of the number of visits to small balls.

•   17 Oct 2014, University of Vienna:
  
  
  • Pawel Pilarczyk (IST Austria):  Perception of transitivity and mixing at finite resolutions.  
    
    
  • Dalia Terhesiu (Vienna):  A renewal scheme for non-uniformly hyperbolic flows.
    
    
  • Carl Dettmann (Bristol):  Stickiness in mushroom billiards.
    
    

•   19 Sept 2014, Budapest University of Technology and Economics:
  
  
  • Zsolt Pajor-Gyulai (Maryland): From averaging to homogenization in cellular flows- an exact description of the transition.
    
    
  • Roland Zweimüller (Vienna): Return- and hitting-time limits for rare events in infinite measure preserving systems.
    
    
  • Domokos Szasz & Peter Balint (Budapest): On the work of Nicolai Chernov.
    

•  13 June 2014, University of Vienna:
  
  • Peyman Eslami (Rome):  Decay of correlations for skew products with discontinuities.
    
    
  • Mohammad Soufi (ICTP Trieste):  Statistical stability for the geometric Lorenz attractor.
    
    
  • Stefano Galatolo (Pisa):  Rigorous computing of the invariant measure in Lorenz like systems.
    

• 8 May 2014,  Budapest University of Technology and Economics:
  
  
  • Nandor Simanyi (Birmingham, AL):  The Boltzmann-Sinai hypothesis: A mystery solved.
    
    
  • Tamas Tel (Budapest):  Absorbing billiards and other dynamical systems.
    
    
  • Oscar Bandtlow (London):  Hölder continuity of the topological entropy for expanding interval maps with holes.
    
    
    
• 7 March 2014,  University of Vienna:  
  
  
  • Mikko Stenlund (Helsinki): Coupling for a random dynamical system.
  
  
  • Damien Thomine (Rennes):  Local time and first return time of periodic semi-flows.
    
    
  • Domokos Szasz (Budapest):  Local ergodicity - a survey.
    
    

• 31 Jan 2014,  Budapest University of Technology and Economics:
  
  
  • Dalia Terhesiu (Vienna): Sharp mixing rates for some infinite measure preserving semiflows.
    
    
  • András Némedy Varga (Budapest): High dimensional generalization of standard pairs and the coupling technique.
    
    

• 13 Dec 2013,  University of Vienna:
  
  

  • Balázs Bárány (Budapest): On the dimension of the graph of the classical Weierstrass functions.
    
    
  • Mathias Beiglböck (Vienna): The Ergodic Theorem, Optimal Transport, and Applications.
    
    
    
• 25 Oct 2013,  Budapest University of Technology and Economics:
  
  
  • Mikko Stenlund (Helsinki): An Adiabatic Dynamical System as a Stochastic Process.
    
    
  • Oliver Butterley (Vienna): The Lorenz flow and some functional analysis.
    
    

• 20 September 2013,  University of Vienna:
  
  
  • Karoly Simon (Budapest):  Slices of generalized Sierpinski carpets. 
    
    
  • Tobias Jäger (Dresden):  Minimal set of torus homeomorphisms.
    
    
  • Evgeny Verbitskiy (Leiden):  Expansivity and homoclinic points in algebraic dynamics.
    
    

• 24 May 2013,  Budapest University of Technology and Economics:
  
  
  
  • Mark Demers (Fairfield):  Perturbations of dispersing billiards via spectral methods.
    
    
  • Zoltan Buczolich (Budapest):  Averages along the squares and related topics.
    
    
  
  
• 12 April 2013,  University of Vienna:
  
  
  • Dalia Terhesiu (Rome): Mixing for some non-uniformly hyperbolic systems with infinite measure.
    
    
  • Marta Tyran-Kaminska (Katowice): Continuous time random walks and limit theorems.
    
    
  • Roland Zweimüller (Vienna): Stochastically stable globally coupled maps with bistable thermodynamic limit.
  
  
  
• 1 March 2013,  Budapest University of Technology and Economics:
  
  
  • Klaus Schmidt (Vienna):  Entropy and periodic points for (commuting) group automorphisms.
    
    
  • Peter Nandori (Budapest):  Lorentz process with shrinking holes in a wall.
    
  
  

• 25 Jan 2013,  University of Vienna:    
  
  
  • Peter Balint (Budapest):  Limit laws and convergence of moments for dispersing billiards with cusps.
    
    
  • Carlangelo Liverani (Rome):  Statistical properties of maps close to a trivial extension.
    
    
  • Gerhard Keller (Erlangen):  Stability index for chaotically driven concave maps.
    
    

• 14 Dec 2012,  Budapest University of Technology and Economics:
  
  
  • Roland Zweimüller (Vienna): Dissipative dynamics as a tool for conservative systems.
    
    
  • Imre Peter Toth (Budapest): Complexity of singularities and growth of unstable manifolds in planar dispersing billiards with corner points.
    

• 23 Nov 2012,  University of Vienna:
  
  • Oliver Butterley (Vienna):  Operator semigroups associated to continuous time dynamical systems.
    
    
  • Peter Nandori (Budapest): On Dettmann's "horizon"-conjectures.
    
    
  • Ian Melbourne (Warwick): Convergence of fast-slow ODEs and maps to stochastic differential equations with multiplicative noise.
    
    

• 21 Sept 2012,  Budapest University of Technology and Economics: 
  
  
  • Henk Bruin (Vienna):   Thermodynamics for Lebesgue dissipative interval maps.
    
    
  • Pablo Shmerkin (Surrey):   Continuity of subadditive Pressure.
    
  
  
  

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      Last update:  20 Jan 2021