Displaying 61 – 80 of 176

Showing per page

On second order Hamiltonian systems

Dana Smetanová (2006)

Archivum Mathematicum

The aim of the paper is to announce some recent results concerning Hamiltonian theory. The case of second order Euler–Lagrange form non-affine in the second derivatives is studied. Its related second order Hamiltonian systems and geometrical correspondence between solutions of Hamilton and Euler–Lagrange equations are found.

On source terms and boundary conditions using arbitrary high order discontinuous Galerkin schemes

Michael Dumbser, Claus-dieter Munz (2007)

International Journal of Applied Mathematics and Computer Science

This article is devoted to the discretization of source terms and boundary conditions using discontinuous Galerkin schemes with an arbitrary high order of accuracy in space and time for the solution of hyperbolic conservation laws on unstructured triangular meshes. The building block of the method is a particular numerical flux function at the element interfaces based on the solution of Generalized Riemann Problems (GRPs) with piecewise polynomial initial data. The solution of the generalized Riemann...

On splitting up singularities of fundamental solutions to elliptic equations in ℂ2

T. Savina (2007)

Open Mathematics

It is known that the fundamental solution to an elliptic differential equation with analytic coefficients exists, is determined up to the kernel of the differential operator, and has singularities on characteristics of the equation in ℂ2. In this paper we construct a representation of fundamental solution as a sum of functions, each of those has singularity on a single characteristic.

On stabilization and control for the critical Klein-Gordon equation on a 3-D compact manifold

Camille Laurent (2011)

Journées Équations aux dérivées partielles

We study the internal stabilization and control of the critical nonlinear Klein-Gordon equation on 3-D compact manifolds. Under a geometric assumption slightly stronger than the classical geometric control condition, we prove exponential decay for some solutions bounded in the energy space but small in a lower norm. The proof combines profile decomposition and microlocal arguments. This profile decomposition, analogous to the one of Bahouri-Gérard [2] on 3 , is performed by taking care of possible...

On the asymptotic behavior for convection-diffusion equations associated to higher order elliptic operators in divergence form.

Mokhtar Kirane, Mahmoud Qafsaoui (2002)

Revista Matemática Complutense

We consider the linear convection-diffusion equation associated to higher order elliptic operators⎧  ut + Ltu = a∇u   on Rnx(0,∞)⎩  u(0) = u0 ∈ L1(Rn),where a is a constant vector in Rn, m ∈ N*, n ≥ 1 and L0 belongs to a class of higher order elliptic operators in divergence form associated to non-smooth bounded measurable coefficients on Rn. The aim of this paper is to study the asymptotic behavior, in Lp (1 ≤ p ≤ ∞), of the derivatives Dγu(t) of the solution of the convection-diffusion equation...

On the Cauchy problem for hyperbolic functional-differential equations

Adrian Karpowicz, Henryk Leszczyński (2015)

Annales Polonici Mathematici

We consider the Cauchy problem for a nonlocal wave equation in one dimension. We study the existence of solutions by means of bicharacteristics. The existence and uniqueness is obtained in W l o c 1 , topology. The existence theorem is proved in a subset generated by certain continuity conditions for the derivatives.

On the Cauchy problem for linear hyperbolic functional-differential equations

Alexander Lomtatidze, Jiří Šremr (2012)

Czechoslovak Mathematical Journal

We study the question of the existence, uniqueness, and continuous dependence on parameters of the Carathéodory solutions to the Cauchy problem for linear partial functional-differential equations of hyperbolic type. A theorem on the Fredholm alternative is also proved. The results obtained are new even in the case of equations without argument deviations, because we do not suppose absolute continuity of the function the Cauchy problem is prescribed on, which is rather usual assumption in the existing...

On the Cauchy problem for linear PDEs with retarded arguments at derivatives

Krzysztof A. Topolski (2015)

Annales Polonici Mathematici

We present an existence theorem for the Cauchy problem related to linear partial differential-functional equations of an arbitrary order. The equations considered include the cases of retarded and deviated arguments at the derivatives of the unknown function. In the proof we use Tonelli's constructive method. We also give uniqueness criteria valid in a wide class of admissible functions. We present a set of examples to illustrate the theory.

Currently displaying 61 – 80 of 176