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Gabriella Zecca

Publications and source records attributed to Gabriella Zecca.

10 recordsLinked to original sources

Well-posedness results for superlinear Fokker-Planck equations

In this manuscript we deal with a class of nonlinear Fokker-Planck equations with the following structure \[ \partial_t u - ÷\big(M\nabla u+ E h(u)\big)=0, \] with $M$ a bounded elliptic matrix, $E$ a vector field in a suitable Lebesgue space, and $h(u)$ featuring a superlinear growth for $u$ large. We provide existence results of $C([0,T),L^1)$ distributional solutions to initial-boundary value problems related to the equation above together with some qualitative properties of solutions.

math.AP↗

Noncoercive quasilinear elliptic operators with singular lower order terms

We consider a family of quasilinear second order elliptic differential operators which are not coercive and are defined by functions in Marcinkiewicz spaces. We prove the existence of a solution to the corresponding Dirichlet problem. The associated obstacle problem is also solved. Finally, we show higher integrability of a solution to the Dirichlet problem when the datum is more regular.

math.AP↗

A multi-species chemotaxis system: Lyapunov functionals, duality, critical mass

We introduce a multi-species chemotaxis type system admitting an arbitrarily large number of population species, all of which are attracted vs. repelled by a single chemical substance. The production vs. destruction rates of the chemotactic substance by the species is described by a probability measure. For such a model we investigate the variational structures, in particular we prove the existence of Lyapunov functionals, we establish duality properties as well as a logarithmic Hardy-Littlewood-Sobolev type inequality for the associated free energy. The latter inequality provides the optimal critical value for the conserved total population mass.

math.AP↗

Mass quantization and minimax solutions for Neri's mean field equation in 2D-turbulence

We study the mean field equation derived by Neri in the context of the statistical mechanics description of 2D-turbulence, under a "stochastic" assumption on the vortex circulations. The corresponding mathematical problem is a nonlocal semilinear elliptic equation with exponential type nonlinearity, containing a probability measure $\mathcal P\in\mathcal M([-1,1])$ which describes the distribution of the vortex circulations. Unlike the more investigated "deterministic" version, we prove that Neri's equation may be viewed as a perturbation of the widely analyzed standard mean field equation, obtained by taking $\mathcal P=δ_1$. In particular, in the physically relevant case where $\mathcal P$ is non-negatively supported and $\mathcal P(\{1\})>0$, we prove the mass quantization for blow-up sequences. We apply this result to construct minimax type solutions on bounded domains in $\mathbb R^2$ and on compact 2-manifolds without boundary.

math.AP↗

Blow-up analysis for some mean field equations involving probability measures from statistical hydrodynamics

Motivated by the mean field equations with probability measure derived by Sawada-Suzuki and by Neri in the context of the statistical mechanics description of two-dimensional turbulence, we study the semilinear elliptic equation with probability measure: {equation*} -Δv=λ\int_I V(α,x,v)e^{αv}\,\Pda -\fracλ{|Ω|}\iint_{I\times\Om}V(α,x,v)e^{αv}\,\Pda dx, {equation*} defined on a compact Riemannian surface. This equation includes the above mentioned equations of physical interest as special cases. For such an equation we study the blow-up properties of solution sequences. The optimal Trudinger-Moser inequality is also considered.

math.AP↗