We consider a reaction-diffusion system exhibiting diffusion driven instability if supplemented by Dirichlet-Neumann boundary conditions. We impose unilateral conditions given by inclusions on this system and prove that global bifurcation of spatially nonhomogeneous stationary solutions occurs in the domain of parameters where bifurcation is excluded for the original mixed boundary value proble...

The interior transmission problem (ITP) is a boundary value problem arising in inverse scattering theory which has important applications in qualitative methods. In this paper, we propose a coupled boundary element and finite element method for the ITP. The coupling procedure is realized by applying the direct boundary integral equation method to define the so-called Dirichlet-to-Neumann (DtN) ...

We consider the inverse problem of determining the time dependent magnetic field of the Schrödinger equation in a bounded open subset of Rn, n ≥ 1, from a finite number of Neumann data, when the boundary measurement is taken on an appropriate open subset of the boundary. We prove the Lispchitz stability of the magnetic potential in the Coulomb gauge class by n times changing initial value suita...

In this paper we study existence and uniqueness of solutions for the boundary-value problem, with initial datum in L1(Ω), ut = div a(x, Du) in (0,∞)×Ω, − ∂u ∂ηa ∈ β(u) on (0,∞)× ∂Ω, u(x, 0) = u0(x) in Ω, where a is a Carathéodory function satisfying the classical Leray-Lions hypothesis, ∂/∂ηa is the Neumann boundary operator associated to a, Du the gradient of u and β is a maximal monotone grap...

Several abstract model problems of elliptic and parabolic type with inhomogeneous initial and boundary data are discussed. By means of a variant of the Dore-Venni theorem, real and complex interpolation, and trace theorems, optimal Lp-regularity is shown. By means of this purely operator theoretic approach, classical results on Lp-regularity of the diffusion equation with inhomogeneous Dirichle...

We provide a direct proof of a quadratic estimate that plays a central role in the determination of domains of square roots of elliptic operators and, as shown more recently, in some boundary value problems with L boundary data. We develop the application to the Kato conjecture and to a Neumann problem. This quadratic estimate enjoys some equivalent forms in various settings. This gives new res...

in this work, by employing the krasnosel'skii fixed point theorem, we study the existence of positive solutions of a three-point boundary value problem for the following fourth-order differential equation begin{eqnarray*} left { begin{array}{ll} u^{(4)}(t) -f(t,u(t),u^{prime prime }(t))=0 hspace{1cm} 0 leq t leq 1, & u(0) = u(1)=0, hspace{1cm} alpha u^{prime prime }(0) - beta u^{prime prim...

In this paper we study existence, uniqueness and solution estimates to the mixed problem r ru = 0 with Dirichlet to Neumann map boundary conditions and Neumann boundary conditions. We then show how this can be used in the reconstruction of , given the relationship between u and its normal derivative on the boundary portion where we do not apply the Dirichlet to Neumann map. A numerical reconstr...

We give explicit representation of Neumann boundary value problem for Bitsadze equation on the upper half plane. will also solution inhomogeneous polyanalytic arising from and (n-1) Dirichlet conditions plane H.