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Perturbation stochastique de processus de rafle

Frédéric Bernicot (2008/2009)

Séminaire Équations aux dérivées partielles

Lors de cet exposé, nous nous intéressons à l’étude de perturbations stochastiques de certaines inclusions différentielles du premier ordre  : les processus de rafle par des ensembles uniformément prox-réguliers. Ce travail nous amène à combiner la théorie des processus de rafle et celle traitant de la reflexion d’un mouvement brownien sur la frontière d’un ensemble. Nous donnerons des résultats traitant du caractère bien-posé de ces inclusions différentielles stochastiques et de leur stabilité.

Perturbed linear rough differential equations

Laure Coutin, Antoine Lejay (2014)

Annales mathématiques Blaise Pascal

We study linear rough differential equations and we solve perturbed linear rough differential equations using the Duhamel principle. These results provide us with a key technical point to study the regularity of the differential of the Itô map in a subsequent article. Also, the notion of linear rough differential equations leads to consider multiplicative functionals with values in Banach algebras more general than tensor algebras and to consider extensions of classical results such as the Magnus...

Pointwise convergence of Boltzmann solutions for grazing collisions in a Maxwell gas via a probabilitistic interpretation

Hélène Guérin (2004)

ESAIM: Probability and Statistics

Using probabilistic tools, this work states a pointwise convergence of function solutions of the 2-dimensional Boltzmann equation to the function solution of the Landau equation for Maxwellian molecules when the collisions become grazing. To this aim, we use the results of Fournier (2000) on the Malliavin calculus for the Boltzmann equation. Moreover, using the particle system introduced by Guérin and Méléard (2003), some simulations of the solution of the Landau equation will be given. This result...

Pointwise convergence of Boltzmann solutions for grazing collisions in a Maxwell gas via a probabilitistic interpretation

Hélène Guérin (2010)

ESAIM: Probability and Statistics


Using probabilistic tools, this work states a pointwise convergence of function solutions of the 2-dimensional Boltzmann equation to the function solution of the Landau equation for Maxwellian molecules when the collisions become grazing. To this aim, we use the results of Fournier (2000) on the Malliavin calculus for the Boltzmann equation. Moreover, using the particle system introduced by Guérin and Méléard (2003), some simulations of the solution of the Landau equation will be given. This result...

Positivity of the density for the stochastic wave equation in two spatial dimensions

Mireille Chaleyat-Maurel, Marta Sanz-Solé (2003)

ESAIM: Probability and Statistics

We consider the random vector u ( t , x ̲ ) = ( u ( t , x 1 ) , ⋯ , u ( t , x d ) ) , where t > 0 , x 1 , ⋯ , x d are distinct points of ℝ 2 and u denotes the stochastic process solution to a stochastic wave equation driven by a noise white in time and correlated in space. In a recent paper by Millet and Sanz–Solé [10], sufficient conditions are given ensuring existence and smoothness of density for u ( t , x ̲ ) . We study here the positivity of such density. Using techniques developped in [1] (see also [9]) based on Analysis on an abstract Wiener space, we characterize the set of...

Positivity of the density for the stochastic wave equation in two spatial dimensions

Mireille Chaleyat–Maurel, Marta Sanz–Solé (2010)

ESAIM: Probability and Statistics

We consider the random vector u ( t , x ̲ ) = ( u ( t , x 1 ) , ⋯ , u ( t , x d ) ) , where t > 0, x1,...,xd are distinct points of ℝ 2 and u denotes the stochastic process solution to a stochastic wave equation driven by a noise white in time and correlated in space. In a recent paper by Millet and Sanz–Solé [10], sufficient conditions are given ensuring existence and smoothness of density for u ( t , x ̲ ) . We study here the positivity of such density. Using techniques developped in [1] (see also [9]) based on Analysis on an abstract Wiener space, we characterize...

Potential confinement property of the parabolic Anderson model

Gabriela Grüninger, Wolfgang König (2009)

Annales de l'I.H.P. Probabilités et statistiques

We consider the parabolic Anderson model, the Cauchy problem for the heat equation with random potential in ℤd. We use i.i.d. potentials ξ:ℤd→ℝ in the third universality class, namely the class of almost bounded potentials, in the classification of van der Hofstad, König and Mörters [Commun. Math. Phys.267 (2006) 307–353]. This class consists of potentials whose logarithmic moment generating function is regularly varying with parameter γ=1, but do not belong to the class of so-called double-exponentially...

Currently displaying 21 – 40 of 79