arXiv subjects

Anne C. Bronzi

Publications and source records attributed to Anne C. Bronzi.

5 recordsLinked to original sources

arXiv2024

On the convergence of trajectory statistical solutions

In this work, a recently introduced general framework for trajectory statistical solutions is considered, and the question of convergence of families of such solutions is addressed. Conditions for the convergence are given which rely on natural assumptions related to a priori estimates for the individual solutions of typical approximating problems. The first main result is based on the assumption that the superior limit of suitable families of compact subsets of carriers of the family of trajectory statistical solutions be included in the set of solutions of the limit problem. The second main result is a version of the former in the case in which the approximating family is associated with a well-posed system. These two results are then applied to the inviscid limit of incompressible Navier-Stokes system in two and three spatial dimensions, showing, in particular, the existence of trajectory statistical solutions to the two- and three-dimensional Euler equations, in the context of weak and dissipative solutions, respectively. Another application of the second main result is on the Galerkin approximations of statistical solutions of the three-dimensional Navier-Stokes equations.

math.AP↗

arXiv2018

Regularity of solutions to a class of variable-exponent fully nonlinear elliptic equations

In the present paper, we propose the investigation of variable-exponent, degenerate/singular elliptic equations in non-divergence form. This current endeavor parallels the by now well established theory of functionals satisfying nonstandard growth condition, which in particular encompasses problems ruled by the $p(x)$-laplacian operator. Under rather general conditions, we prove viscosity solutions to variable exponent fully nonlinear elliptic equations are locally of class $C^{1,κ}$ for a universal constant $0< κ< 1$. A key feature of our estimates is that they do not depend on the modulus of continuity of exponent coefficients, and thus may be employed to investigate a variety of problems whose ellipticity degenerates and/or blows-up in a discontinuous fashion.

math.AP↗

arXiv2015

Abstract Framework for the Theory of Statistical Solutions

An abstract framework for the theory of statistical solutions is developed for general evolution equations, extending the theory initially developed for the three-dimensional incompressible Navier-Stokes equations. The motivation for this concept is to model the evolution of uncertainties on the initial conditions for systems which have global solutions that are not known to be unique. Both concepts of statistical solution in trajectory space and in phase space are given, and the corresponding results of existence of statistical solution for the associated initial value problems are proved. The wide applicability of the theory is illustrated with the very incompressible Navier-Stokes equations, a reaction-diffusion equation, and a nonlinear wave equation, all displaying the property of global existence of weak solutions without a known result of global uniqueness.

math.AP↗

arXiv2013

Global existence of a weak solution of the incompressible Euler equations with helical symmetry and $L^p$ vorticity

We prove the global existence of a helical weak solution of the 3D Euler equations, in full space, for an initial velocity with helical symmetry, without swirl and whose initial vorticity is compactly supported in the axial plane and belongs to $L^p$, for some $p>\frac{4}{3}$. This result is an extension of the existence part of the work of B. Ettinger and E. Titi (SIAM J. Math Anal. 41(2009) 269-296), who studied well-posedness of the Euler equations with helical symmetry without swirl, with bounded initial vorticity, in a helical pipe.

math.AP↗

arXiv2013

On the convergence of statistical solutions of the 3D Navier-Stokes-$α$ model as $α$ vanishes

In this paper statistical solutions of the 3D Navier-Stokes-$α$ model with periodic boundary condition are considered. It is proved that under certain natural conditions statistical solutions of the 3D Navier-Stokes-$α$ model converge to statistical solutions of the exact 3D Navier-Stokes equations as $α$ goes to zero. The statistical solutions considered here arise as families of time-projections of measures in suitable trajectory spaces.

math.AP↗