Truncation method for operators with disconnected essential spectrum
نویسنده
چکیده
In this short paper, the usage of truncation method to get information about essential spectrum of bounded as well as semi-bounded linear operators on separable Hilbert spaces, is investigated. In addition to this, the problem of predicting the gaps in the essential spectrum of self-adjoint operators, linear algebraically is also considered.
منابع مشابه
Self-commutators of composition operators with monomial symbols on the Bergman space
Let $varphi(z)=z^m, z in mathbb{U}$, for some positive integer $m$, and $C_varphi$ be the composition operator on the Bergman space $mathcal{A}^2$ induced by $varphi$. In this article, we completely determine the point spectrum, spectrum, essential spectrum, and essential norm of the operators $C^*_varphi C_varphi, C_varphi C^*_varphi$ as well as self-commutator and anti-self-commutators of $C_...
متن کاملSpectrum and essential spectrum of linear combinations of composition operators on the Hardy space H2
Let -----. For an analytic self-map --- of --- , Let --- be the composition operator with composite map --- so that ----. Let --- be a bounded analytic function on --- . The weighted composition operator --- is defined by --- . Suppose that --- is the Hardy space, consisting of all analytic functions defined on --- , whose Maclaurin cofficients are square summable. .....
متن کاملFrom Unbounded to Bounded Domains: the Fate of Point and Essential Spectrum
The existence and stability of travelling waves are typically investigated on unbounded domains even though the domains in experiments or numerical simulations are bounded. We are interested in the eeects that the truncation of the unbounded to a large but bounded domain has on the stability properties of a nonlinear wave. These eeects depend upon the boundary conditions that are imposed on the...
متن کاملMeasure of non strict singularity of Schechter essential spectrum of two bounded operators and application
In this paper, we discuss the essential spectrum of sum of two bounded operators using measure of non strict singularity. Based on this new investigation, a problem of one-speed neutron transport operator is presented.
متن کاملStability of essential spectra of bounded linear operators
In this paper, we show the stability of Gustafson, Weidmann, Kato, Wolf, Schechter and Browder essential spectrum of bounded linear operators on Banach spaces which remain invariant under additive perturbations belonging to a broad classes of operators $U$ such $gamma(U^m)
متن کامل