Using the general argument in Borel resummation of perturbation theory that links the divergent perturbation theory to the nonperturbative effect we argue that the nonperturbative effect associated with the perturbation theory should have a branch cut along the positive real axis in the complex coupling plane. The component in the weak coupling expansion of the nonperturbative amplitude, which ...

We consider the following nonlinear Schrödinger system in R3 {− u + P(|x |)u = μu3 + βv2u, x ∈ R3, − v + Q(|x |)v = νv3 + βu2v, x ∈ R3, where P(r) and Q(r) are positive radial potentials, μ > 0, ν > 0 and β ∈ R is a coupling constant. This type of system arises, in particular, in models in Bose– Einstein condensates theory. We examine the effect of nonlinear coupling on the solution structure. ...

Biochemical regulatory networks governing diverse cellular processes such as stress-response, differentiation and cell cycle often contain coupled feedback loops. We aim at understanding how features of feedback architecture, such as the number of loops, the sign of the loops and the type of their coupling, affect network dynamical performance. Specifically, we investigate how bistability range...

abstract       background and objective: the spread of drug resistance in bacteria have prompted researchers to seek suitable alternative for antimicrobial drugs among various medicinal plants and nanoparticles. the aim of this study was to evaluate the effect of silver nanoparticles alone and in combination with methanol extract of zataria multiflora on five gram-positive and gram-negative bac...

The magnetic polarization of a Pt capping layer leads to an increase of the interisland magnetic coupling in a two-dimensional array of Fe islands. For small superparamagnetic islands, Pt deposition leads to a superparamagnetic–ferromagnetic transition. For larger ferromagnetic but weakly coupled islands, Pt deposition produces a stronger interisland coupling. Polar Kerr spectroscopy measuremen...

where E is the longitudinal electric field and Ex,y and By,x are the transverse electric and magnetic fields excited by the beam. Coupling impedances can be determined through bench measurement [1], analytically [2] or numerically by solving a discretized form of Maxwell’s equations [3]. This work focuses on finding suitable methods for the numerical calculation of coupling impedances for the r...

The effect of wood flour and coupling agent content on the hygroscopic thickness swelling rate of polypropylene composites was investigated in this study. To meet this objective, the wood flour was compounded with polypropylene and coupling agent in an internal mixer; then the samples were fabricated by injection molding. The concentration was varied from 40 to 60% for wood flour and from 0 to ...

Abstract We discuss the properties of fermion propagator in three dimensional QED with dressed photon based on spectral representation with LSZ reduction formula.We evaluate the spectral function by the sum of infinite numbers of rainbow type diagram for intermediate states.In this method we have the solution as one derived by renormalization group in four-dimension.Massless vacuum polarization...

The current strategy to achieve high luminosity for high energy physics experiments as well as high brilliance in synchrotron radiation sources is to store huge currents distributed in many bunches in circular machines. This approach has the disadvantage that the performance of these machines is most likely to be limited by coupled bunch instabilities. To circumvent this problem strong feedback...