Some statements acknowledging support from PRODYN for research visits


Alberto Adrego Pinto

I have benefited from Prodyn program in several ways. The Prodyn grant gave finantial support to several meetings in Portugal: Mini Workshop on "Recent Trends in Dynamics" 17 - 22 January 2000, International Conference on "Dynamical Systems" 8 - 13 May 2000, Workshop on "Recent Trends in Dynamics II" 7 - 11 May 2001, Mini-Workshop on "Recent Trends in Dynamics III" 6 - 11 May 2002, International Workshop on "Dynamical Systems and Ergodic theory" 7 - 11 July 2003. It also gave me finantial support to participate in several conferences where I had the opportunity to present my work and to interact and develop scientific research projects with several colleges. Many Thanks

  • Pinto A A and Rand D A, Existence, uniqueness and ratio decomposition for Gibbs states via duality. Erg. Th. Dyn. Syst. {\bf 21} (2001) 533-544.
  • Pinto A A and Rand D A, Teichm\"uller spaces and HR structures for hyperbolic surface dynamics. Erg. Th. Dyn. Syst. {\bf 22} (2002) 1905-1931.
  • Pinto A A and Rand D A, Smoothness of holonomies for codimension 1 hyperbolic dynamics. Bull. London Math. Soc. {\bf 34} (2002) 341-352.
  • Pinto A A and Rand D A, Rigidity of hyperbolic sets on surfaces Jornal London Math. Soc. (to appear).


    Serge Troubetzoy (troubetz@iml.univ-mrs.fr)

    I profited from PRODYN in several ways. First I invited Tyll Krueger and Henk Bruin for visits. The resulting papers from these collaborations are on your web page along with the following preprint:

  • ``Topological and Symbolic Dynamics for Axiom A Diffeomorphisms with Holes'' S. Bundfuss, T. Krueger, S. Troubetzkoy

    Also the support of PRODYN allowed me to organize a wonderful ``Workshop on Piecewise Isometries'' whose web page still proudly acknowledges PRODYN's support: http://math.sfsu.edu/goetz/conference/pi/


    From: Prof. Dr. Manfred Denker (denker@math.uni-goettingen.de)

    Here is a list of publications partially sponsored by PRODYN Conferences:

  • M. Denker, M. Gordin, S.M. Heinemann: On the relative variational principle for fibre expanding maps. Ergodic Theory and Dynamical Systems {\bf 22} (2002), 757--782.
  • J. Aaronson, M. Denker: Group extensions of Gibbs-Markov maps. Probab. Theory and Related Fields {\bf 123} (2002), 28--40.
  • Manuel Stadlbauer: The Bowen-Series map for some free groups. PhD-Dissertation, G\"ottingen 2002.
  • Marc Kesseböhmer: Large deviation for weak Gibbs measures and multifractal spectra. Nonlinearity 14, No.2, 395-409 (2001).
  • Mario Roy: Gibbs families for fibrewise expansive systems. PhD-Dissertation, G\"ottingen 2000.
  • Oliver Schmitt: Remarks on the generator-problem. PhD-Dissertation, G\"ottingen 2001.
  • Mario Roy: Fibrewise expansive systems. Topology Appl. 124, No.3, 373-396 (2002).

    The main stream of research in the interplay between fractal geometry, probability theory and dynamical systems has been devoted for a long time to dynamical systems with invariant hyperbolic probabilities, and has largely ignored those systems with infinite invariant measures or measures describing parabolic or intermittent situations.

    During the last years we made progress in
    1. Unifying the approach to multifractals and stochastics using Ruelles zeta-function. (kesseb\"ohmer, Denker)
    2. Finding new conditions for a function to be aperiodic (no coboundary condition), which does not rely on Leonovs approach. Applications to local limit theorems and the infinite ergodic theory of Fuchsian groups. (Aaronson, Denker, Sarig, Stadlbauer, Zweim\"uller)
    3. Thermodynamics in the relative setting given by a factor. (Denker, Gordin, Heinemann, Roy, Schmidt)


    From: Xavier BRESSAUD (bressaud@iml.univ-mrs.fr)

    The prodyn program was a great opportunity for me as a young researcher. I could attend various meeting organised with the support of this program, where I met the community of searchers working in the area I am interested in. I used the program of short visits in both ditections with Roland Zweimuller (in Erlangen at this time) and Carlangelo Liverani (in Roma) in both directions. I wrote a paper with each of them. Also I appreciated this program as a meeting organiser. The meetings TREC (2000) and L'odyssee Dynamique (2001) got an important amount of money from ESF, and would not have been so intersting without this money.

  • X. Bressaud, R. Zweimuller. Non exponential law of entrance times in asymptotically rare events for intermittent maps with infinite invariant measure. Annales Henri Poincarré 2 (2001) 1 - 12.
  • X. Bressaud and C. Liverani, Anosov diffeomorphism and coupling, Ergodic Theory and Dynamical Systems, 22, n. 1, pp. 129--152, (2002). http://www.mat.uniroma2.it/~liverani/pubblicazioni.html Xavier BRESSAUD
    From: Anna Zdunik (aniazd@duch.mimuw.edu.pl)

  • Veronique Maume-Deschamps, Bernard Schmitt, Mariusz Urbanski, Anna Zdunik: Pressure and recurrence, Fund. Math 178 (2003)129-141 (appeared as a preprint in 2001)

    (in this paper I wrote my thanks to PRODYN for supporting my visit to Dijon in 2000)

    Moreover, I would like to mention that I participated in conferences supported by PRODYN (probably): Paris 2001 and Warvick symposia in April and July 2003. My living costs at these conferences and the cost of one trip to Warwick were covered by the organizers. During these two Warwick meetings I worked (with Mariusz Urbanski) on the final version of two papers:

  • Mariusz Urbanski, Anna Zdunik: Geometry and ergodic theory of non-hyperbolic exponential maps (preprint 2003)
  • Mariusz Urbanski, Anna Zdunik: The parabolic map ${1\over e}e^z$. (preprint 2003)

    Both papers have been submitted for publication.


    From: Carlangelo Liverani (liverani@mat.uniroma2.it)

    Personally, PRODYN allowed me to interact with V. Maume-Deschamps, G.Keller, M.Blank, V.Baladi, M.Bendicks, S.Luzzatto, M.Pollicott with which I have collaborated, and published, or I am collaborating at the moment. In particular, my discussions with M.Pollicott, V.Baldi and M.Bendicks have been instrumental for my work on flows in which exponential decay of correlations is established for all smooth geodesic flows (On Contact Anosov flows, to appear in Annals of Mathematics). More generally, my students and the students of several Italian collegues have greatly benefited from the many activities of PRODYN devoted to the training of young researches. At the european level, I feel that probably the most important achievement of PRODYN is the fact that an entiere new generation of european researched in the field of Dynamical Systems has built professional relations at the european level that, inevitably, will shape their future work in the field. In addition, they have absorbed an image of the field at the european level that has created a common language allowing them to easily communicate across the field subdivisions and the national flavors.

    The relevant papers are already on the (new) web page.


    From: Viviane Baladi (baladi@math.jussieu.fr)

    The PRODYN grant allowed me to organise a winter school in Switzerland, to participate to several inspiring meetings, in particular in Warwick and Porto (where I could interact both with european and latin american colleagues), and more importantly, to make possible short visits of senior (Benedicks) and younger colleagues (Baillif) with a minimum of hassle. A very important feature of this grant was that the bureaucracy is reduced to a minimum: this is essential to conduct productive research. I must say that I already miss PRODYN, and that I feel very much that the ergodic theoretical community in Europe needs another such grant.

    I think it made us aware of the "actors" in the european dynamics scene: there are certainly not more "local nodes" specialising in dynamics, even Orsay, Stockholm and Warwick may lose this title eventually (I hope not). However, there are more and more strong individuals or small clusters scattered all over Europe, and PRODYN allowed them to interact freely and productively.

    Papers with PRODYN supported collaborations:

  • V. Baladi, H.H Rugh, Floquet spectrum of weakly coupled map lattices, Comm. Math. Phys., 220, 561-582 (2001) http://www.math.jussieu.fr/~baladi/
  • V. Baladi, M. Benedicks and V. Maume-Deschamps, Almost sure rates of mixing for i.i.d. unimodal maps, Ann. E.N.S., 35 77-126 (2002); Corrigendum Ann. E.N.S., 36 319-322 (2003) http://www.math.jussieu.fr/~baladi/
  • V. Baladi, H.-H. Rugh and Y. Jiang, Dynamical determinants via dynamical conjugacies for postcritically finite polynomials, J. Stat. Phys., 108, 973-993 (2002) http://www.math.jussieu.fr/~baladi/
  • V. Baladi and M. Baillif, Kneading determinants and spectra of transfer operators in higher dimensions, the isotropic case, Preprint (revised version, submitted to ETDS, 2003) http://www.math.jussieu.fr/~baladi/
  • V. Baladi, E. Pujals, and M. Sambarino, Dynamical zeta functions for analytic surface diffeomorphisms with dominated splitting, Preprint (2003), submitted for publication


    From: Krzysztof Fraczek (fraczek@mat.uni.torun.pl)

    Participation in PRODYN program allowed me to extend of my research to areas connected with smooth ergodic theory (before that I worked only in abstract ergodic theory) and to meet great matematicians. Discussion with them influenced on the progress in my research.

    Papers which PRODYN supported (partially):

  • K. Fraczek, Linear growth of the derivative for measure--preserving diffeomorphisms, Coll. Math. 84/85 Part 1 (2000),147-157. Preprint(2000). http://www.ma.ic.ac.uk/~luzzato/Prodyn/php/papers.php3
  • K. Fraczek, Measure--preserving diffeomorphisms of the torus, Erg. Th. Dynam. Sys. 21 (2001), 1759-1781. Preprint (2000). http://www.ma.ic.ac.uk/~luzzato/Prodyn/php/papers.php3
  • K. Fraczek, Polynomial growth of the derivatives for diffeomorphisms on tori, to appear in Disc. Cont. Dynam. Sys. Preprint (2002). http://arxiv.org/abs/math.DS/0205044
  • K. Fraczek, On cocycles with values in the group SU(2), Monatsh. Math 131 (2000), 279-307. Preprint (2000). http://arxiv.org/abs/math.DS/0002120
  • K. Fraczek, On the dergree of cocycles with values in the group SU(2), to appear in Isr. J. Math. Preprint (2002).
    From: Xavier Buff (buff@picard.ups-tlse.fr)

  • X. Buff, A.L. Epstein, A parabolic Pommerenke-Levin-Yoccoz inequality, Fundamenta Mathematicae 172 (2002) 249-289.

    PRODYN enabled an exchange between Toulouse and Coventry during which the two authors wrote the article.


    From: Feliks PRZYTYCKI (F.Przytycki@impan.gov.pl)

    Due to several mutual short visits in Warwick, Warsaw and Stockholm we have been able to develop a theory of topological Collet-Eckmann maps and a theory of pressure for iteration of rational functions. The following papers resulted:

  • F. Przytycki, J. Rivera-Letelier, S. Smirnov. Equivalence and topological invariance of conditions for non-uniform hyperbolicity in iteration of rational maps, Inventiones Mathematicae 151 (2003), 29-63.
  • F. Przytycki, J. Rivera-Letelier, S. Smirnov. Equality of pressures for rational functions, Preprint, to appear in Ergodic Theory and Dynamical Systems. http://www.impan.gov.pl/~feliksp/publ.html
    From: Jerome Buzzi (buzzi@daphne.math.polytechnique.fr)

    PRODYN has been instrumental in allowing me to collaborate more closely and more productively with various other researchers in other countries of the program. Important results have been achieved with minimum administrative overhead in the thermodynamical formalism of piecewise expanding maps in higher dimensions.

    The following papers are relevant to PRODYN:

  • J. Buzzi, G. Keller, Zeta functions and transfer operators for multidimensional piecewise affine and expanding maps, Ergod. Th. &Dynam. Sys. 21(2001), 690-716. http://www.mi.uni-erlangen.de/~keller/english_index.html
  • J. Buzzi, Markov partitions for piecewise monotonic maps, preprint 2003. http://math.polytechnique.fr/cmat/buzzi/markovpmm.pdf
  • J. Buzzi, O. Sarig, Uniqueness of equilibrium measures for countable Markov shifts and multi-dimensional piecewise expanding maps. Ergodic th. and dynam. syst. 23 (2003), 1383-1400. Preprint 2001. http://math.polytechnique.fr/cmat/buzzi/uniequ.pdf
  • J. Buzzi, V. Maume-Deschamps, Decay of correlations for piecewise invertible maps in higher dimensions, Israel J. Math., 131 (2002), 203-220. Preprint 2001. http://math.polytechnique.fr/cmat/buzzi/correlpwi.pdf
  • J. Buzzi, F. Paccaut and B. Schmitt, Conformal measures for multidimensional piecewise invertible maps, Ergodic th. and dynam. syst. 21 (2001), 1035--1049. Preprint 1997. http://math.polytechnique.fr/cmat/buzzi/conformal.ps
    From: Toby Hall (t.hall@liverpool.ac.uk)

    I received funding from PRODYN to attend the conference "Dynamical Systems and Ergodic Theory" in Katsiveli (Crimea), 21-30 August 2000.

    This conference was of great benefit to my research - in addition to the obvious benefits of attending excellent research talks and minicourses, I was able to advance my collaboration with Andre de Carvalho while there, and also met Nikita Sidorov for the first time, whom I've had many useful conversations with since.

    The following papers had some input from discussions taking place during the conference (the first is in the conference proceedings):

  • A. de Carvalho, T. Hall Symbolic dynamics and topological models in dimensions 1 and 2, in "Topics in Dynamics and Ergodic Theory", ed. S. Bezuglyi and S. Kolyada, LMS Lecture note series 310, (2003), pp. 40-59.
  • A. de Carvalho, T. Hall Braid forcing and star-shaped train tracks, to appear in Topology. (http://www.liv.ac.uk/maths/PURE/MIN_SET/CONTENT/members/T_Hall.html)
    From: Stanislav Smirnov (stas@e.kth.se)

    PRODYN greatly helped two of my joint research projects by funding a few research visits, in particular for the following paper:

  • F. Przytycki, J. Rivera-Letelier and S. Smirnov Equality of pressures for rational functions, Ergodic Theory Dynam. Systems, to appear http://www.math.kth.se/~stas/paper/index.html
    From: Pierre Collet (Pierre.Collet@cpht.polytechnique.fr)

    First another reference:

  • P.Collet, J.-P.Eckmann. A Rigorous Upper Bound for the Propagation Speed for the Swift-Hohenberg Equation and Related Equations. J. Stat. Phys. {\bf 108}, 1107-1124 (2002).

    I have benefited from Prodyn in several ways. First by participating to conferences (Warsaw, Cargese) where I had contacts with colleagues and learned new results and techniques. Also a cross visit Geneva/Paris allowed us with J.-P.Eckmann to continue our work on extended systems, developping the theory of extensive quantities like epsilon entropy, topological entropy per unit length, and also the problem of estimating propagation speed of solutions in parabolic systems.

    I have benefited a lot from Prodyn and so have many people in France. It was a wonderfull and very successful enterprise and I want to thank and congratulate you personnaly for this success.