Resolvent and spectrum of a nonselfadjoint differential operator in a Hilbert space

Resolvent and spectrum of a nonselfadjoint differential operator in a Hilbert space

We consider a second order regular differential operator whose coefficients are nonselfadjoint bounded operators acting in a Hilbert space. An estimate for the resolvent and a bound for the spectrum are established. An operator is said to be stable if its spectrum lies in the right half-plane. By the obtained bounds, stability and instability conditions are established.

Operator Preconditioning in Hilbert Space

2010 1 Introduction The numerical solution of linear elliptic partial differential equations consists of two main steps: discretization and iteration, where generally some conjugate gradient method is used for solving the finite element discretization of the problem. However, when for elliptic problems the dis-cretization parameter tends to zero, the required number of iterations for a prescrib...

a contrastive analysis of concord and head parameter in english and azerbaijani

این پایان نامه به بررسی و مقایسه دو موضوع مطابقه میان فعل و فاعل (از نظر شخص و مشار) و هسته عبارت در دو زبان انگلیسی و آذربایجانی می پردازد. اول رابطه دستوری مطابقه مورد بررسی قرار می گیرد. مطابقه به این معناست که فعل مفرد به همراه فاعل مفرد و فعل جمع به همراه فاعل جمع می آید. در انگلیسی تمام افعال، بجز فعل بودن (to be) از نظر شمار با فاعلشان فقط در سوم شخص مفرد و در زمان حال مطابقت نشان میدهند...

a contrastive study of rhetorical functions of citation in iranian and international elt scopus journals

writing an academic article requires the researchers to provide support for their works by learning how to cite the works of others. various studies regarding the analysis of citation in m.a theses have been done, while little work has been done on comparison of citations among elt scopus journal articles, and so the dearth of research in this area demands for further investigation into citatio...

Operator Extensions on Hilbert Space