The Donnachie-Landshoff fit of total cross sections has now become a standard reference for models of total, elastic and diffractive cross-sections. Adopting their philosophy that simple-pole exchanges should account for all data to present energies, we assess the uncertainties on their fits. Our best estimate for the pomeron intercept is 1.096 +0.012 −0.009 , but several models have a good χ 2 for intercepts in the range [1.07,1.11].

The Chern-Simons theories on a noncommutative plane, which is shown to be describing the quantum Hall liquid, is considered. We introduce matter fields fundamentally coupled to the noncommutative Chern-Simons field. Exploiting BPS equations for the nonrelativistic Chern-Simons theory, we find the exact solutions of multi vortices that are closely packed and exponentially localized. We determine the position, the size and the angular momentum explicitly. We then construct solutions of two spatially separated vortex, and determine the moduli dependence of the size and the angular momentum. We also consider the relativistic Chern-Simons theory and find nontopological solutions whose properties are similar to the nonrelativistic counterpart. However, unlike the nonrelativistic case, there are two branches of solutions for a given magnetic field and they cease to exist below certain noncommutativity scale. * Electronic Mail: dsbak@mach.uos.ac.kr † The Seiberg-Witten map is a way to find the local gauge invariant quantities [32].

We study the ultraviolet divergent structures of the matter ͑scalar͒ field in a higher D-dimensional ReissnerNordström black hole and compute the matter field contribution to the Bekenstein-Hawking entropy by using the Pauli-Villars regularization method. We find that the matter field contribution to the black hole entropy does not, in general, yield the correct renormalization of the gravitational coupling constants. In particular, we show that the matter field contribution in odd dimensions does not give the term proportional to the area of the black hole event horizon. ͓S0556-2821͑97͒06104-3͔

We show that the quantum dynamics of a real scalar field for a large class of potentials in the symmetric Gaussian state, where nonperturbative quantum contributions are taken into account, can be described equivalently by a two-dimensional nonlinear dynamical system with a definite angular momentum ͓U͑1͒ charge of a complex theory͔. A proposal is put forward that the symmetric Gaussian state with a nearly minimal uncertainty and a large quantum fluctuation, as an initial condition, naturally explains most of the essential features of the early stage of the inflationary universe. ͓S0556-2821͑98͒02024-4͔PACS number͑s͒: 98.80.Cq, 04.62.ϩv

We consider the nonrelativistic field theory with a quartic interaction on a noncommutative plane and compute the 2-->2 scattering amplitude within perturbative analysis to all orders. We regain the results of the perturbative analysis by finding the scattering and the bound state wave functions of the two particle Schrodinger equation. These wave functions unusually have two center positions in the relative coordinates, whose separation is transverse to the total momentum and scales linearly with its magnitude, exhibiting the stringy nature of the noncommutative field theory.