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# Videothèque  | enregistrements trouvés : 12

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## Multi angle  Tilings and non-intersecting paths beyond integrable cases Gorin, Vadim (Auteur de la Conférence) | CIRM (Editeur )

The talk is about a class of systems of 2d statistical mechanics, such as random tilings, noncolliding walks, log-gases and random matrix-type distributions. Specific members in this class are integrable, which means that available exact formulas allow delicate asymptotic analysis leading to the Gaussian Free Field, sine-process, Tracy-Widom distributions. Extending the results beyond the integrable cases is challenging. I will speak about a recent progress in this direction: about universal local limit theorems for a class of lozenge and domino tilings, noncolliding random walks; and about GFF-type asymptotic theorems for global fluctuations in these systems and in discrete beta log­gases. The talk is about a class of systems of 2d statistical mechanics, such as random tilings, noncolliding walks, log-gases and random matrix-type distributions. Specific members in this class are integrable, which means that available exact formulas allow delicate asymptotic analysis leading to the Gaussian Free Field, sine-process, Tracy-Widom distributions. Extending the results beyond the integrable cases is challenging. I will speak about a ...

## Multi angle  Low temperature interfaces and level lines in the critical prewetting regime Ioffe, Dmitry (Auteur de la Conférence) | CIRM (Editeur )

Complete wetting in the context of the low temperature two-dimensional Ising model is characterized by creation of a mesoscopic size layer of the "-" phase above an active substrate. Adding a small positive magnetic field h makes "-"-phase unstable, and the layer becomes only microscopically thick. Critical prewetting corresponds to a continuous divergence of this layer as h tends to zero. There is a conjectured 1/3 (diffusive) scaling leading to Ferrari-Spohn diffusions. Rigorous results were established for polymer models of random and self-avoiding walks under vanishing area tilts.
A similar 1/3-scaling is conjectured to hold for top level lines of low temperature SOS-type interfaces in three dimensions. In the latter case, the effective local structure is that of ordered walks, again under area tilts. The conjectured scaling limits (rigorously established in the random walk context) are ordered diffusions driven by Airy Slatter determinants.
Based on joint walks with Senya Shlosman, Yvan Velenik and Vitali Wachtel.
Complete wetting in the context of the low temperature two-dimensional Ising model is characterized by creation of a mesoscopic size layer of the "-" phase above an active substrate. Adding a small positive magnetic field h makes "-"-phase unstable, and the layer becomes only microscopically thick. Critical prewetting corresponds to a continuous divergence of this layer as h tends to zero. There is a conjectured 1/3 (diffusive) scaling leading ...

## Multi angle  A 2d growth model in the anisotropic KPZ class Toninelli, Fabio (Auteur de la Conférence) | CIRM (Editeur )

Dimer models provide natural models of (2+1)-dimensional random discrete interfaces and of stochastic interface dynamics. I will discuss two examples of such dynamics, a reversible one and a driven one (growth process). In both cases we can prove the convergence of the stochastic interface evolution to a deterministic PDE after suitable (diffusive or hyperbolic respectively in the two cases) space-time rescaling.
Based on joint work with B. Laslier and M. Legras.
Dimer models provide natural models of (2+1)-dimensional random discrete interfaces and of stochastic interface dynamics. I will discuss two examples of such dynamics, a reversible one and a driven one (growth process). In both cases we can prove the convergence of the stochastic interface evolution to a deterministic PDE after suitable (diffusive or hyperbolic respectively in the two cases) space-time rescaling.
Based on joint work with B. ...

## Multi angle  Multi-time distribution of periodic TASEP Baik, Jinho (Auteur de la Conférence) | CIRM (Editeur )

We consider periodic TASEP with periodic step initial condition, and evaluate the joint distribution of the locations of m particles. For arbitrary indices and times, we find a formula for the multi-time, multi-space joint distribution in terms of an integral of a Fredholm determinant. We then discuss the large time limit in the so-called relaxation scale. The one-point distributions for other initial conditions are also going to discussed.
Based on joint work with Zhipeng Liu (NYU).
We consider periodic TASEP with periodic step initial condition, and evaluate the joint distribution of the locations of m particles. For arbitrary indices and times, we find a formula for the multi-time, multi-space joint distribution in terms of an integral of a Fredholm determinant. We then discuss the large time limit in the so-called relaxation scale. The one-point distributions for other initial conditions are also going to discus...

## Multi angle  Arithmétique à virgule flottante : plaie ou terrain de jeu ? Boldo, Sylvie (Auteur de la Conférence) | CIRM (Editeur )

Nous confions à nos ordinateurs de nombreux calculs mais la machine a des limites due à son arithmétique dite à virgule flottante. D'une part chaque calcul est effectué avec un certain nombre de chiffres (souvent environ 15 chiffres décimaux) et donc chaque calcul peut créer une erreur, certes faible, mais qui peut s'accumuler avec les précédentes pour fournir un résultat complètement faux. D'autre part, les valeurs que l'ordinateur appréhende ont des limites vers l'infiniment petit et l'infiniment grand. Hors de ces bornes, l'ordinateur produit des valeurs spéciales souvent inattendues. La première partie de cet exposé montrera que l'ordinateur n'est pas infaillible ou plutôt que son utilisation est parfois abusive. La seconde partie consisitera en une utilisation judicieuse de l'arithmétique flottante de façon à récupérer les erreurs ou à garantir un calcul
presque juste, même dans les cas pathologiques.
Nous confions à nos ordinateurs de nombreux calculs mais la machine a des limites due à son arithmétique dite à virgule flottante. D'une part chaque calcul est effectué avec un certain nombre de chiffres (souvent environ 15 chiffres décimaux) et donc chaque calcul peut créer une erreur, certes faible, mais qui peut s'accumuler avec les précédentes pour fournir un résultat complètement faux. D'autre part, les valeurs que l'ordinateur appréhende ...

## Multi angle  On the analysis of a class of thermodynamically compatible viscoelastic fluids with stress diffusion Málek, Josef (Auteur de la Conférence) | CIRM (Editeur )

We first summarize the derivation of viscoelastic (rate-type) fluids with stress diffusion that generates the models that are compatible with the second law of thermodynamics and where no approximation/reduction takes place. The approach is based on the concept of natural configuration that splits the total response between the current and initial configuration into the purely elastic and dissipative part. Then we restrict ourselves to the class of fluids where elastic response is purely spherical. For such class of fluids we then provide a mathematical theory that, in particular, includes the long-time and large-data existence of weak solution for suitable initial and boundary value problems. This is a joint work with Miroslav Bulicek, Vit Prusa and Endre Suli. We first summarize the derivation of viscoelastic (rate-type) fluids with stress diffusion that generates the models that are compatible with the second law of thermodynamics and where no approximation/reduction takes place. The approach is based on the concept of natural configuration that splits the total response between the current and initial configuration into the purely elastic and dissipative part. Then we restrict ourselves to the class ...

## Multi angle  An asymptotic regime for the Vlasov-Poisson system Miot, Evelyne (Auteur de la Conférence) | CIRM (Editeur )

We investigate the gyrokinetic limit for the two-dimensional Vlasov-Poisson system in a regime studied by F. Golse and L. Saint-Raymond. First we establish the convergence towards the Euler equation under several assumptions on the energy and on the norms of the initial data. Then we provide a first analysis of the asymptotics for a Vlasov-Poisson system describing the interaction of a bounded density with a moving point charge.

## Multi angle  Large time behavior of solutions to 3-D MHD system with initial data near equilibrium Zhang, Ping (Auteur de la Conférence) | CIRM (Editeur )

Given initial data $(b_0, u_0)$ close enough to the equilibrium state $(e_3, 0)$, we prove that the 3-D incompressible MHD system without magnetic diffusion has a unique global solution $(b, u)$. Moreover, we prove that $(b(t) - e_3, u(t))$ decay to zero with rates in both $L^\infty$ and $L^2$ norm. (This is a joint work with Wen Deng).

## Multi angle  $L^q$-$L^r$ estimates of a generalized Oseen evolution operator, with applications to the Navier-Stokes flow past a rotating obstacle Hishida, Toshiaki (Auteur de la Conférence) | CIRM (Editeur )

Consider the motion of a viscous incompressible fluid in a 3D exterior domain $D$ when a rigid body $\mathbb R^3\setminus D$ moves with prescribed time-dependent translational and angular velocities. For the linearized non-autonomous system, $L^q$-$L^r$ smoothing action near $t=s$ as well as generation of the evolution operator $\{T(t,s)\}_{t\geq s\geq 0}$ was shown by Hansel and Rhandi [1] under reasonable conditions. In this presentation we develop the $L^q$-$L^r$ decay estimates of the evolution operator $T(t,s)$ as $(t-s)\to\infty$ and then apply them to the Navier-Stokes initial value problem. Consider the motion of a viscous incompressible fluid in a 3D exterior domain $D$ when a rigid body $\mathbb R^3\setminus D$ moves with prescribed time-dependent translational and angular velocities. For the linearized non-autonomous system, $L^q$-$L^r$ smoothing action near $t=s$ as well as generation of the evolution operator $\{T(t,s)\}_{t\geq s\geq 0}$ was shown by Hansel and Rhandi [1] under reasonable conditions. In this presentation we ...

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