Results 21 to 30 of about 596 (38)

Structure of the tree component in an area of riparian forest in the Piratini River Basin, Rio Grande do Sul, Brazil [PDF]

Biotemas, 2009
The vegetation studied belongs to the Pampa biome. The vegetation of this region is described as Open Arboreal Savanna because it presents a herb stratum and an arboreal stratum with a gallery forest.
Luciano Rodrigues Soares, Rogério Soares Ferrer   +1 more
doaj  

On the stability of self-adjointness of linear relations

, 2019
This paper focuses on the stability of self-adjointness of linear relations under perturbations in Hilbert spaces. It is shown that a self-adjoint relation is still self-adjoint under bounded and relatively bounded perturbations.
Liu, Yan
core   +1 more source

Taylor approximations of operator functions

, 2013
This survey on approximations of perturbed operator functions addresses recent advances and some of the successful methods.Comment: 12 ...
A Skripka, A Skripka, A Skripka, A Skripka, AB Aleksandrov, AH Chamseddine, AV Rybkin, D Potapov, D Potapov, D Potapov, D Potapov, D Potapov, DR Yafaev, E Kissin, F Gesztesy, H Neidhardt, J-M Bouclet, K Dykema, K Dykema, MG Krein, MG Krein, MS Birman, MS Birman, NA Azamov, NA Azamov, NA Azamov, RW Carey, S Lord, VM Adamjan, VV Peller, WD Suijlekom van, YB Farforovskaya, YB Farforovskaya, YB Farforovskaya, YL Daleckii   +34 more
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Nilpotent perturbations of m-isometric and m-symmetric tensor products of commuting d-tuples of operators

Demonstratio Mathematica
If T1{{\mathbb{T}}}_{1} and T2{{\mathbb{T}}}_{2} are commuting dd-tuples of Hilbert space operators in B(ℋ)dB{\left({\mathcal{ {\mathcal H} }})}^{d} such that (T1*⊗I+I⊗T2*,T1⊗I+I⊗T2)\left({{\mathbb{T}}}_{1}^{* }\otimes I+I\otimes {{\mathbb{T}}}_{2}^{* },{
Duggal Bhagwati Prashad, Kim In Hyoun
doaj   +1 more source

Point Interactions: PT-Hermiticity and Reality of the Spectrum

, 2002
General point interactions for the second derivative operator in one dimension are studied. In particular, ${\mathcal P \mathcal T}$-self-adjoint point interactions with the support at the origin and at points $\pm l$ are considered. The spectrum of such
Albeverio, S., Fei, S. M., Kurasov, P.
core   +1 more source

Quantitative bounds on the discrete spectrum of non self-adjoint quantum magnetic Hamiltonians [PDF]

, 2016
We establish Lieb-Thirring type inequalities for non self-adjoint relatively compact perturbations of certain operators of mathematical physics. We apply our results to quantum Hamiltonians of Schr{\"o}dinger and Pauli with constant magnetic field of ...
Sambou, Diomba
core  

Exponential decay of eigenfunctions of first order systems

, 2007
For first order systems, we obtain an efficient bound on the exponential decay of an eigenfunction in terms of the distance between the corresponding eigenvalue and the essential spectrum.
Yafaev, D. R.
core   +3 more sources

Perturbation Theory for the Quantum Time-Evolution in Rotating Potentials

, 2002
The quantum mechanical time-evolution is studied for a particle under the influence of an explicitly time-dependent rotating potential. We discuss the existence of the propagator and we show that in the limit of rapid rotation it converges strongly to ...
Enss, Volker, Kostrykin, Vadim, Schrader, Robert   +2 more
core   +2 more sources

Variation of discrete spectra for non-selfadjoint perturbations of selfadjoint operators

, 2013
Let B=A+K where A is a bounded selfadjoint operator and K is an element of the von Neumann-Schatten ideal S_p with p>1. Let {\lambda_n} denote an enumeration of the discrete spectrum of B.
E.B. Davies, I.C. Gohberg, L. Golinskii, M. Hansmann, M. Hansmann, M. Hansmann, M.I. Gil’, Marcel Hansmann, P. The Lai, R. Bhatia, R. Bhatia, R. Bhatia, R. Bhatia, R. Bouldin, T. Kato, V.I. Macaev, W. Kahan   +16 more
core   +1 more source

On Cayley Identity for Self-Adjoint Operators in Hilbert Spaces [PDF]

, 2011
We prove an analogue to the Cayley identity for an arbitrary self-adjoint operator in a Hilbert space. We also provide two new ways to characterize vectors belonging to the singular spectral subspace in terms of the analytic properties of the resolvent ...
Alexander V. Kiselev, N. Naboko, Serguei
core