The search session has expired. Please query the service again.
Some electromagnetic materials have, in a given frequency range, an effective dielectric permittivity and/or a magnetic permeability which are real-valued negative coefficients when dissipation is neglected. They are usually called metamaterials. We study a scalar transmission problem between a classical dielectric material and a metamaterial, set in an open, bounded subset of Rd, with d = 2,3. Our aim is to characterize occurences where the problem is well-posed within the Fredholm (or coercive...
Some electromagnetic materials have, in a given frequency range, an effective dielectric permittivity and/or a magnetic permeability which are real-valued negative coefficients when dissipation is neglected. They are usually called metamaterials. We study a scalar transmission problem between a classical dielectric material and a metamaterial, set in an open, bounded subset of Rd, with d = 2,3. Our aim is to characterize occurences where the problem is well-posed within the Fredholm (or coercive...
We describe a joint work with C.E. Kenig and G. Uhlmann [9] where we improve an earlier result by Bukhgeim and Uhlmann [1], by showing that in dimension , the knowledge of the Cauchy data for the Schrödinger equation measured on possibly very small subsets of the boundary determines uniquely the potential. We follow the general strategy of [1] but use a richer set of solutions to the Dirichlet problem.
We study the uniqueness and regularity of Leray-Hopf's weak solutions for the MHD equations with dissipation and resistance in different frameworks. Using different kinds of space-time estimates in conjunction with the Littlewood-Paley-Bony decomposition, we present some general criteria of uniqueness and regularity of weak solutions to the MHD system, and prove the uniqueness and regularity criterion in the framework of mixed space-time Besov spaces by applying Tao's trichotomy method.
The change in the electric potential due to lightning is evaluated.
The potential along the lightning channel is a constant which is
the projection of the pre-flash potential along a piecewise harmonic
eigenfunction which is constant along the lightning channel.
The change in the potential outside the lightning channel is a harmonic
function whose boundary conditions
are expressed in terms of the pre-flash potential and
the post-flash potential along the lightning channel.
The expression for the...
The mathematical analysis on various mathematical models arisen in semiconductor science has attracted a lot of attention in both applied mathematics and semiconductor physics. It is important to understand the relations between the various models which are different kind of nonlinear system of P.D.Es. The emphasis of this paper is on the relation between the drift-diffusion model and the diffusion equation. This is given by a quasineutral limit from the DD model to the diffusion equation.
In this paper, we study a Zakharov system coupled to an electron diffusion equation in order to describe laser-plasma interactions. Starting from the Vlasov-Maxwell system, we derive a nonlinear Schrödinger like system which takes into account the energy exchanged between the plasma waves and the electrons via Landau damping. Two existence theorems are established in a subsonic regime. Using a time-splitting, spectral discretizations for the Zakharov system and a finite difference scheme for the...
In this paper, we study a Zakharov system coupled to an electron
diffusion equation in order to describe laser-plasma interactions. Starting from
the Vlasov-Maxwell system, we derive a nonlinear Schrödinger
like system which takes into account the energy exchanged between the plasma waves and the electrons
via Landau damping. Two existence theorems are established in a subsonic regime.
Using a time-splitting, spectral discretizations for the Zakharov system and a
finite difference scheme for...
We consider a boundary optimal control problem for the Maxwell system with a final value cost criterion. We introduce a time domain decomposition procedure for the corresponding optimality system which leads to a sequence of uncoupled optimality systems of local-in-time optimal control problems. In the limit full recovery of the coupling conditions is achieved, and, hence, the local solutions and controls converge to the global ones. The process is inherently parallel and is suitable for real-time...
We consider a boundary optimal control problem for the Maxwell system with a
final value cost criterion. We introduce a time domain decomposition procedure
for the corresponding optimality system which leads to a sequence of
uncoupled optimality systems of local-in-time optimal control problems. In
the limit full recovery of the coupling conditions is achieved, and, hence,
the local solutions and controls converge to the global ones. The process is
inherently parallel and is suitable for real-time...
The electromagnetic initial-boundary value problem for a cavity enclosed by perfectly conducting walls is considered. The cavity medium is defined by its permittivity and permeability which vary continuously in space. The electromagnetic field comes from a source in the cavity. The field is described by a magnetic vector potential satisfying a wave equation with initial-boundary conditions. This description through is rigorously shown to give a unique solution of the problem and is the starting...
Currently displaying 1 –
18 of
18