Two-photon detachment from the F− negative ion has been investigated within the lowest order perturbation theory. We show that in accordance with the adiabatic theory a proper asymptotic behaviour of the 2p bound state wave function is crucial for obtaining correct absolute values of the multiphoton detachment cross sections. We find that the latter are substantially higher than it was previous...

We study second order perturbation theory for embedded eigenvalues of an abstract class of self-adjoint operators. Using an extension of the Mourre theory, under assumptions on the regularity of bound states with respect to a conjugate operator, we prove upper semicontinuity of the point spectrum and establish the Fermi Golden Rule criterion. Our results apply to massless Pauli-Fierz Hamiltonia...

The nonperturbative nature of inter-nucleon interactions is explored by varying the momentum cutoff of a two-nucleon potential. Conventional force models, which have large cutoffs, are nonperturbative because of strong short-range repulsion, the iterated tensor interaction, and the presence of bound or nearly-bound states. But for low-momentum interactions with cutoffs around 2 fm −1 , the soft...

We develop a perturbation method that generalizes an approach proposed recently to treat velocity–dependent quantum–mechanical models. In order to test present approach we apply it to some simple trivial and nontrivial examples. PACS. 03.65.Ge Solutions of wave equations: bound states

We introduce the extended perturbation method, which improves accuracy of standard by reducing approximation errors under certainty equivalence. For New Keynesian model with Calvo pricing, is more accurate than perturbation, implies explosive dynamics because it omits upper bound on inflation implied this model. In contrast, enforces and generates stable dynamics. also show that can accurately ...

We address the minimization of regularized convex cost functions which are customarily used for edge-preserving restoration and reconstruction of signals and images. In order to accelerate computation, the multiplicative and the additive half-quadratic reformulation of the original cost-function have been pioneered in Geman & Reynolds (1992) and Geman & Yang (1995). The alternate minimization o...

In this paper, let A and B be n x p complex tensors = + E. Denote the T-Drazin inverse of by AD. We give a perturbation bound for ||BD-AD||=||AD|| under condition (W). Considering solution singular tensor equation A* b, (b ? R(AD)) at same time. The optimal system equations have been given.

In a lossless periodic structure, bound state in the continuum (BIC) is characterized by real frequency and Bloch wave vector for which there exist waves propagating to or from infinity surrounding media. For applications, it important analyze high-$Q$ resonances that either naturally vectors near of BIC appear when structure perturbed. Existing theories provide quantitative results complex (an...

We provide a systematic derivation of the scaling behaviour of various quantities and, in particular, establish the scale invariance of the ionization probability. We discuss the gauge invariance of the scaling properties and the manner in which they can be exploited as a consistency check in explicit analytical expressions, in perturbation theory, in the Kramers–Henneberger and Floquet approxi...

The light-front heavy quark effective theory is derived to all orders in 1/mQ. In the limit mQ → ∞, the theory exhibits the familiar heavy quark spinflavor symmetry. This new formalism permits a straightforward canonical quantization to all orders in 1/mQ; moreover, higher order terms have rather simple operator structures. The light-front heavy quark effective theory can serve as an useful fra...