arXiv subjects

B. Ferrario

Publications and source records attributed to B. Ferrario.

7 recordsLinked to original sources

arXiv2013

Inviscid limit of stochastic damped 2D Navier-Stokes equations

We consider the inviscid limit of the stochastic damped 2D Navier- Stokes equations. We prove that, when the viscosity vanishes, the stationary solution of the stochastic damped Navier-Stokes equations converges to a stationary solution of the stochastic damped Euler equation and that the rate of dissipation of enstrophy converges to zero. In particular, this limit obeys an enstrophy balance. The rates are computed with respect to a limit measure of the unique invariant measure of the stochastic damped Navier-Stokes equations.

math.PR↗

arXiv2010

Well posedness of a stochastic hyperviscosity-regularized 3D Navier-Stokes equation

We analyse the well posedness of a stochastic hyperviscosity-regularized 3D Navier-Stokes equation; this is the Navier-Stokes equation in which the Laplace operator is replaced by its a-power for a>1. We prove existence and uniqueness for this equation assuming a>= 5/4.

math.AP↗

arXiv2008

Some examples of absolute continuity of measures in stochastic fluid dynamics

A non linear Ito equation in a Hilbert space is studied by means of Girsanov theorem. We consider a non linearity of polynomial growth in suitable norms, including that of quadratic type which appears in the Kuramoto-Sivashinsky equation and in the Navier-Stokes equation. We prove that Girsanov theorem holds for the 1-dimensional stochastic Kuramoto-Sivashinsky equation and for a modification of the 2- and 3-dimensional stochastic Navier-Stokes equation. In this way, we prove existence and uniqueness of solutions for these stochastic equations. Moreover, the asymptotic behaviour for large time is characterized.

math.PR↗

arXiv2007

Invariant measures for a stochastic Kuramoto-Sivashinky equation

For the 1-dimensional Kuramoto-Sivashinsky equation with random forcing term, existence and uniqueness of solutions is proved. Then, the Markovian semigroup is well defined; its properties are analyzed, in order to provide sufficient conditions for existence and uniqueness of invariant measures for this stochastic equation. Finally, regularity results are presented.

math.PR↗

arXiv2006

2D Navier-Stokes equation in Besov spaces of negative order

The Navier--Stokes equation in the bidimensional torus is considered, with initial velocity and forcing term in suitable Besov spaces. Results of local existence and uniqueness are proven; under further restriction on the indexes defining the Besov speces involved, we prove global existence.

math.AP↗

arXiv2006

On a stochastic version of Prouse model in fluid dynamics

A stochastic version of a modified Navier-Stokes equation (introduced by Prouse) is considered in a 3-dimensional torus. We prove existence and uniqueness of martingale solutions. A different model with the non linearity given by a power 5 of the velocity is analyzed; for the structure function of this model, some insights towards an expression similar to that obtained by the Kolmogorov 1941 theory of turbulence are presented.

math.PR↗

arXiv2004

Uniqueness of solutions of the stochastic Navier-Stokes equation with invariant measure given by the enstrophy

A stochastic Navier-Stokes equation with space-time Gaussian white noise is considered, having as infinitesimal invariant measure a Gaussian measure μ_ν whose covariance is given in terms of the enstrophy. Pathwise uniqueness for μ_ν-a.e. initial velocity is proven for solutions having μ_ν as invariant measure.

math.PR↗