The so-called Hallén integral equation for the current on a finite linear antenna center-driven by a delta-function generator takes two forms depending on the choice of kernel. The two kernels are… (More)

Conditions are established for the existence of a scattering length and an effective range in the low-energy expansion of the S-wave phase-shift of a central potential in two and three dimensions.… (More)

We present an extension to πp and Kp elastic scattering at high energies of the impactpicture phenomenology we first proposed more than twenty years ago, for pp and p̄p elastic scattering. We show,… (More)

When the electron density is a linear function of distance, it is known that the MSW equations for two neutrino species can be solved in terms of known functions. It is shown here that more… (More)

Among the various profound but solvable models tion [41 of physics, two of the most studied are the Korteweg— d2v 1 dv 2 1 dv 1 de Vries (KdV) equation for nonlinear wave phenom—i + —(av~+ i3) + ‘yu3… (More)

We show that the rising total photoproduction cross section recently observed at HERA is entirely consistant with the impact-picture in the theory of expanding protons which was proposed more than… (More)

One very common interaction between the individuals of a group is the tendency to imitate each other. Under certain conditions this might be expected to critically affect the behaviour of the group… (More)

In this paper we study the number of bound states for potentials in one and two spatial dimensions. We first show that in addition to the well-known fact that an arbitrarily weak attractive potential… (More)

We present results on the stability of quantum systems consisting of a negative charge −q1 with mass m1 and two positive charges q2 and q3, with masses m2 and m3, respectively. We show that, for… (More)

We derive a bound on the total number of negative energy bound states in a potential in two spatial dimensions by using an adaptation of the Schwinger method to derive the BirmanSchwinger bound in… (More)