BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Henk Bruin\, Olga Lukina (University of Vienna) DTSTART:20210209T130000Z DTEND:20210209T150000Z DTSTAMP:20260404T110653Z UID:DobMathSeminar/1 DESCRIPTION:Title: Rotated Odometers\nby Henk Bruin\, Olga Lukina (Universi ty of Vienna) as part of Dobrushin Mathematics Laboratory Seminar\n\n\nAbs tract\nWe consider infinite interval exchange transformations (IETs) obtai ned \nas a composition of a finite IET and the von Neumann-Kakutani map\, \ncalled rotated odometers\, and study their dynamical and ergodic \nprope rties by means of an associated Bratteli-Vershik system. \nWe show that ev ery rotated odometer is measurably isomorphic to \nthe first return map of a rational parallel flow on a translation \nsurface of finite area with i nfinite genus and a finite number of \nends\, with respect to the Lebesgue measure. This is one motivation \nfor the study of rotated odometers. We also prove a few results \nabout the factors of the unique aperiodic minim al subsystem of a \nrotated odometer.\n LOCATION:https://stable.researchseminars.org/talk/DobMathSeminar/1/ END:VEVENT BEGIN:VEVENT SUMMARY:Carlangelo Liverani (University of Roma) DTSTART:20210223T130000Z DTEND:20210223T150000Z DTSTAMP:20260404T110653Z UID:DobMathSeminar/2 DESCRIPTION:Title: Locating Ruelle resonances\nby Carlangelo Liverani (Univ ersity of Roma) as part of Dobrushin Mathematics Laboratory Seminar\n\n\nA bstract\nRuelle resonances can be expressed either in terms of the Laplace \ntransform of the correlation functions or as point spectrum of the \nRu elle Transfer operator. While the first point of view is closer \nto what can be measured observing the system\, the latter is much \nmore efficient for the mathematical investigation. Unfortunately\, \nthere are no genera l techniques to identify precisely the point \nspectrum. I will present an approach that can provide some \ninformation and can be applied in a vari ety of hyperbolic \ndynamical systems. The approach is not really new\, as traces of \nit can be found already in Ruelle's original work\, yet it ap pears \nthat it was never explored or presented systematically.\n LOCATION:https://stable.researchseminars.org/talk/DobMathSeminar/2/ END:VEVENT BEGIN:VEVENT SUMMARY:Evgeny Verbitskiy (University of Leiden) DTSTART:20210302T130000Z DTEND:20210302T150000Z DTSTAMP:20260404T110653Z UID:DobMathSeminar/3 DESCRIPTION:Title: Absolutely continuous invariant measures for random dynamica l systems\nby Evgeny Verbitskiy (University of Leiden) as part of Dobr ushin Mathematics Laboratory Seminar\n\n\nAbstract\nI will give an overvie w of two recent results on the existence of\nabsolutely continuous invaria nt measures (acim) for random \ninterval transformations\, comprising of ' good' (hyperbolic) and \n'bad' (non-hyperbolic) maps.\nIt turns out that e ven in the case when a random dynamical system \nadmits a finite acim\, i. e.\, when the good guys win\, the density \nof the invariant measure is le ss smooth than in a purely hyperbolic \ncase. For example\, the random mix ture of the Gauss and Renyi \ncontinued fractions maps has a very smooth\, but not real-analytic\, \ninvariant density.\n LOCATION:https://stable.researchseminars.org/talk/DobMathSeminar/3/ END:VEVENT BEGIN:VEVENT SUMMARY:Conference DTSTART:20210309T080000Z DTEND:20210309T160000Z DTSTAMP:20260404T110653Z UID:DobMathSeminar/4 DESCRIPTION:Title: International online conference dedicated to the anniversary of R.A. Minlos\nby Conference as part of Dobrushin Mathematics Labora tory Seminar\n\n\nAbstract\nInternational online conference dedicated to t he anniversary of R.A. Minlos. \nThe conference will consist of two sessio ns - morning (from 11:00 Moscow time)\nand evening (from 15:00 Moscow time ).\nFor complete information on the conference with program and Zoom link\ , see\nhttp://iitp.ru/ru/userpages/74/285.htm\n LOCATION:https://stable.researchseminars.org/talk/DobMathSeminar/4/ END:VEVENT BEGIN:VEVENT SUMMARY:Yuri Kondratiev (University of Bielefeld) DTSTART:20210323T130000Z DTEND:20210323T150000Z DTSTAMP:20260404T110653Z UID:DobMathSeminar/5 DESCRIPTION:Title: Random time dynamical systems\nby Yuri Kondratiev (Unive rsity of Bielefeld) as part of Dobrushin Mathematics Laboratory Seminar\n\ n\nAbstract\nWe consider two types of random time dynamics: \n- Markov pr ocesses in random time\, \n- Random time dynamical systems. \nIn both case s we are interested in the long time asymptotics \nfor related evolution e quations and\, especially\, in the effects \nof random time changes.\n LOCATION:https://stable.researchseminars.org/talk/DobMathSeminar/5/ END:VEVENT BEGIN:VEVENT SUMMARY:Michael Blank (IITP RAS) DTSTART:20210330T130000Z DTEND:20210330T150000Z DTSTAMP:20260404T110653Z UID:DobMathSeminar/6 DESCRIPTION:Title: Dynamics of piecewise isometries of the torus\nby Michae l Blank (IITP RAS) as part of Dobrushin Mathematics Laboratory Seminar\n\n \nAbstract\nBy now\, we have learned reasonably well how to study hyperbol ic \n(locally expanding/contracting or both) chaotic dynamical systems\, \ nthanks to a large extent to the development of the so called \noperator a pproach. Contrary to this almost nothing is known about \npiecewise isomet ries\, except for a special case of one-dimensional \ninterval exchange ma ppings. The last case is fundamentally different \nfrom the general situat ion in the obvious presence of an invariant \nmeasure (Lebesgue measure)\, which helps a lot in the analysis. \nWe will show that already the restri ction of the rotation of the \nplane to a torus demonstrates a number of r ather unexpected properties.\nOur main results give sufficient conditions for the existence/absence \nof invariant measures of general piecewise iso metries of the torus. \nThe analysis of simple ergodic properties of these measures is also carried out.\n LOCATION:https://stable.researchseminars.org/talk/DobMathSeminar/6/ END:VEVENT BEGIN:VEVENT SUMMARY:B.M. Gurevich (IITP & MSU) DTSTART:20210413T130000Z DTEND:20210413T150000Z DTSTAMP:20260404T110653Z UID:DobMathSeminar/7 DESCRIPTION:Title: On sequences of equilibrium measures corresponding to finite subgraphs of an infinite loaded graph\nby B.M. Gurevich (IITP & MSU) as part of Dobrushin Mathematics Laboratory Seminar\n\n\nAbstract\nВ до кладе будет рассказано о до конца еще не решенной задаче\, относящейся \nк термоди намическому формализму для символическ их цепей Маркова. \nРечь пойдет о понятии равновесной меры m\, т.е. вероятностной ме ре на \nфазовом пространстве динамическо й системы\, максимизирующей разность меж ду\nметрической энтропией этой системы и интегралом от функции f. В нашем \nслучае динамическая система - это сдвиг в прост ранстве последовательностей\, \nсостояще м из путей счетного ориентированного гр афа G\, а f зависит лишь \nот конечного числ а элементов последовательности. Мы выяс ним\, условия \nсуществования m (если G свя зен\, она единственна) и проанализируем с лучай \nконечного связного подграфа граф а G\, когда этот подграф в естественном \nс мысле возрастает и стремится ко всему G.\n LOCATION:https://stable.researchseminars.org/talk/DobMathSeminar/7/ END:VEVENT BEGIN:VEVENT SUMMARY:Sergey Foss (NSU & Heriot-Watt Uni) DTSTART:20210420T130000Z DTEND:20210420T150000Z DTSTAMP:20260404T110653Z UID:DobMathSeminar/8 DESCRIPTION:Title: Longest and heaviest paths in barak-erdos directed random gr aphs and related models\nby Sergey Foss (NSU & Heriot-Watt Uni) as par t of Dobrushin Mathematics Laboratory Seminar\n\n\nAbstract\nWe analyse as ymptotic properties (SLLN\, FCLT\, etc.) of paths of maximal length \nin a class of acyclic directed random graphs. For that\, we need an auxiliary \ninfinite bin model. Next\, we introduce a perfect simulation algorithm f or \nestimating the growth rate of maximal paths. \nThen we consider some generalizations of the model (edges have random \nweights\, complete order ing is replaced by partial one\, etc.)\nIn a particular case of a parametr ic family of two-point distributions\, \nwe discuss amusing properties of (non)differentiability of the growth \nrate w.r. to the parameter. If time allows\, we show how do Poisson forest\, \nTracy-Widom distribution and f urther exotics do appear in this setting.\nThis is a joint work with Takis Konstantopoulos and several other authors.\n LOCATION:https://stable.researchseminars.org/talk/DobMathSeminar/8/ END:VEVENT BEGIN:VEVENT SUMMARY:Andrey Pyatnitsky (IITP RAS) DTSTART:20210518T130000Z DTEND:20210518T150000Z DTSTAMP:20260404T110653Z UID:DobMathSeminar/9 DESCRIPTION:Title: Energy averaging on a two-dimensional Poisson point process< /a>\nby Andrey Pyatnitsky (IITP RAS) as part of Dobrushin Mathematics Labo ratory Seminar\n\n\nAbstract\nРассматривается модель Изинга при нулевой температуре на пуасс оновском \nточечном процессе на плоскост и. При естественной нормировке изучаем \n асимптотические свойства последователь ностей функций конечной энергии.\n LOCATION:https://stable.researchseminars.org/talk/DobMathSeminar/9/ END:VEVENT BEGIN:VEVENT SUMMARY:Conference in the honour of the 75th anniversary of Alexander I. K omech (IITP RAS) DTSTART:20210525T130000Z DTEND:20210525T150000Z DTSTAMP:20260404T110653Z UID:DobMathSeminar/10 DESCRIPTION:Title: Conference in the honour of the 75th anniversary of Alexand er I. Komech\nby Conference in the honour of the 75th anniversary of A lexander I. Komech (IITP RAS) as part of Dobrushin Mathematics Laboratory Seminar\n\n\nAbstract\nConference in the honour of the 75th anniversary of Alexander I. Komech\n\n16:00 Aleksei Ilyin (Keldysh Inst. of Applied Math ematics): Two-sided dimension estimates of the attractor of the damped d riven Euler–Bardina equations in two and three dimensions\n17:00 Sergei Kuksin (Inst. Math. de Jussieu): The K41 theory of turbulence and its rig orous one-dimensional model\n18:15 Alexander Shnirelman (Concordia Uni): S oliton asymptotics in hydrodynamics.\n\nSee details at: http://comech.sdf .org/events/du-2021/\n LOCATION:https://stable.researchseminars.org/talk/DobMathSeminar/10/ END:VEVENT BEGIN:VEVENT SUMMARY:Francois Baccelli (UT Austin and INRIA) DTSTART:20210601T130000Z DTEND:20210601T150000Z DTSTAMP:20260404T110653Z UID:DobMathSeminar/11 DESCRIPTION:Title: Replica-mean-field limits for intensity-based neural networ ks\nby Francois Baccelli (UT Austin and INRIA) as part of Dobrushin Ma thematics Laboratory Seminar\n\n\nAbstract\nDue to the inherent complexity of neural models\, relating the spiking \nactivity of a network to its st ructure requires simplifying assumptions\, \nsuch as considering models in the thermodynamic mean-field limit. \nIn this limit\, an infinite number of neurons interact via vanishingly \nsmall interactions\, thereby erasing the finite size geometry of interactions. \nTo better capture the geometr y in question\, we analyze the activity of \nneural networks in the replic a-mean-field limit regime. Such models are made \nof infinitely many repli cas which interact according to the same basic \nstructure as that of the finite network of interest. Our main contribution \nis an analytical chara cterization of the stationary dynamics of intensity-based \nneural network s with spiking reset and heterogeneous excitatory synapses in \nthis repli ca-mean-field limit. Specifically\, we functionally characterize \nthe sta tionary dynamics of these limit networks via ordinary or partial \ndiffere ntial equations derived from the Poisson Hypothesis of queuing theory. \nW e then reduce this functional characterization to a system of self-consist ency \nequations specifying the stationary neuronal firing rates. \nJoint work with T. Taillefumier.\n LOCATION:https://stable.researchseminars.org/talk/DobMathSeminar/11/ END:VEVENT BEGIN:VEVENT SUMMARY:Oleg Musin (IITP RAS) DTSTART:20210608T130000Z DTEND:20210608T150000Z DTSTAMP:20260404T110653Z UID:DobMathSeminar/12 DESCRIPTION:Title: Circle packings on a sphere\, contact graphs\, and Steiner- Soddy-type theorems\nby Oleg Musin (IITP RAS) as part of Dobrushin Mat hematics Laboratory Seminar\n\n\nAbstract\nВ докладе будет р ассказано о связи между упаковками шаро в в n-мерном пространстве\, \nкоторые каса ются заданного семейства шаров\, и сфери ческими кодами. Эта связь \nпозволяет обо бщить классические теоремы Штейнера и С одди о цепочках кругов \nи шаров. В размер ностях 3 и 4\, таким упаковкам шаров соотв етствуют 3-сферические \nкоды\, то есть уп аковки сферических шапочек на сфере. Это т случай будет рассмотрен \nболее деталь но и показано как классификация контакт ных графов приводит к новым \nрезультата м о сферических упаковках.\n LOCATION:https://stable.researchseminars.org/talk/DobMathSeminar/12/ END:VEVENT BEGIN:VEVENT SUMMARY:Andrey Dymov (IMRAS\, HSE) DTSTART:20210622T130000Z DTEND:20210622T150000Z DTSTAMP:20260404T110653Z UID:DobMathSeminar/13 DESCRIPTION:Title: On the Zakharov-Lvov stochastic model of wave turbulence\nby Andrey Dymov (IMRAS\, HSE) as part of Dobrushin Mathematics Laborato ry Seminar\n\n\nAbstract\nТеория волновой турбулент ности (ВТ) была создана в 1960х годах В.Е. За харовым \nи его школой как эвристический метод для изучения малоамплитудных реше ний \nнелинейных гамильтоновых УрЧП с пе риодическими граничными условиями боль шого \nпериода L>>1. С тех пор ВТ интенсивно развивается в физических работах\, одна ко \nматематические результаты\, посвяще нные обоснованию теории\, начали появлят ься \nтолько в последнее время.\nОсновная задача ВТ — изучение поведения одной из главных характеристик решения \nуравнен ия\, называемой энергетическим спектром\ , в пределе период L -> \\infty\, \nамплитуда ре шения \\nu -> 0. \nЯ расскажу о своих совместн ых работах с С.Б. Куксиным\, A.Maiocchi и С.Г. Вл эдуцем\, \nв которых мы изучаем две против оположные последовательности пределов в для \nнелинейного уравнения Шредингера \, подверженного действию слабых случайн ого \nвозмущения и вязкости. Полученные р езультаты отличается от предсказанного ранее \nв физических работах.\n LOCATION:https://stable.researchseminars.org/talk/DobMathSeminar/13/ END:VEVENT BEGIN:VEVENT SUMMARY:Yuri Suhov (Penn State University) DTSTART:20210914T130000Z DTEND:20210914T150000Z DTSTAMP:20260404T110653Z UID:DobMathSeminar/14 DESCRIPTION:Title: Hard spheres on $Z^3$: Kepler's conjecture on a lattice and high-density Gibbs measures\nby Yuri Suhov (Penn State University) as part of Dobrushin Mathematics Laboratory Seminar\n\nAbstract: TBA\n LOCATION:https://stable.researchseminars.org/talk/DobMathSeminar/14/ END:VEVENT END:VCALENDAR