Results 31 to 40 of about 1,194 (210)

The Faddeev Equation and the Essential Spectrum of a Model Operator Associated with the Hamiltonian of a Nonconserved Number of Particles

Advances in Mathematical Physics, 2014
A model describing a truncated operator H (truncated with respect to the number of particles) and acting in the direct sum of zero-, one-, and two-particle subspaces of fermionic Fock space FaL2T3 over L2(T3) is investigated.
Zahriddin Muminov, Fudziah Ismail, Jamshid Rasulov   +2 more
doaj   +1 more source

On the limit spectrum of a degenerate operator in the framework of periodic homogenization or singular perturbation problems

Comptes Rendus. Mathématique, 2022
In this paper we perform the analysis of the spectrum of a degenerate operator $A_\varepsilon $ corresponding to the stationary heat equation in a $\varepsilon $-periodic composite medium having two components with high contrast diffusivity.
Sili, Ali
doaj   +1 more source

The phase-resolved high energy spectrum of the crab pulsar [PDF]

Advances in Space Research, 2007
15 pages, 4 figures To appear in Advances in Space Science ...
Cheng, KS, Takata, J, Tang, APS, Chang, HK, Jia, JJ   +4 more
openaire   +4 more sources

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

, 2012
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.
Gil’, Michael
core   +1 more source

Resolvent-Generated Generalized Spectral Operators for Nonlinear Dynamical Systems via Koopman Semigroups

Mathematics
Spectral methods form a cornerstone of linear dynamics, where evolution is resolved into harmonic modes governed by eigenvalues and spectral measures of normal operators.
Rui A. P. Perdigão
doaj   +1 more source

Probing multiple-frequency atom-photon interactions with ultracold atoms

New Journal of Physics, 2019
We dress atoms with multiple-radiofrequency (RF) fields and investigate the spectrum of transitions driven by an additional probe field. A complete theoretical description of this rich spectrum is presented, in which we find allowed transitions and ...
K Luksch, E Bentine, A J Barker, S Sunami, T L Harte, B Yuen, C J Foot   +6 more
doaj   +1 more source

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

, 2016
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.
Gil’, Michael
core   +1 more source

Norm-resolvent convergence in perforated domains

, 2018
For several different boundary conditions (Dirichlet, Neumann, Robin), we prove norm-resolvent convergence for the operator −Δ in the perforated domain Ω∖⋃i∈2εZdBaε(i), aε≪ε, to the limit operator −Δ+μι on L2(Ω), where μι∈Cis a constant depending on the ...
Rösler, Frank, Cherednichenko, Kirill D., Dondl, Patrick   +2 more
core   +1 more source

G-Convergence of Dirac Operators

Journal of Function Spaces and Applications, 2012
We consider the linear Dirac operator with a (−1)-homogeneous locally periodic potential that varies with respect to a small parameter. Using the notation of G-convergence for positive self-adjoint operators in Hilbert spaces we prove G-compactness in ...
Hasan Almanasreh, Nils Svanstedt
doaj   +1 more source

Pseudo-hermitian random matrix models: General formalism

Nuclear Physics B, 2022
Pseudo-hermitian matrices are matrices hermitian with respect to an indefinite metric. They can be thought of as the truncation of pseudo-hermitian operators, defined over some Krein space, together with the associated metric, to a finite dimensional ...
Joshua Feinberg, Roman Riser
doaj   +1 more source