ar X iv : c on d - m at / 9 51 21 19 v 1 1 5 D ec 1 99 5 Two Lane Traffic Simulations using Cellular Automata

ar X iv : c on d - m at / 9 51 10 37 v 1 7 N ov 1 99 5 CELLULAR AUTOMATA FOR TRAFFIC FLOW : ANALYTICAL RESULTS

We use analytical methods to investigate cellular automata for traffic flow. Two different mean-field approaches are presented, which we call site-oriented and car-oriented, respectively. The car-oriented mean-field theory yields the exact fundamental diagram for the model with maximum velocity vmax = 1 whereas in the site-oriented approach one has to take into account correlations between near...

ar X iv : c on d - m at / 9 51 21 60 v 1 2 2 D ec 1 99 5 Spin - reflection positivity of the Kondo lattice at half - filling

We examine the spin-reflection positivity of the ground state of the Kondo lattice model at half-filling with the antiferromagnetic and ferromagnetic exchange couplings J = 0. For every positive U > 0, where U is the Coulomb interaction between the conduction electrons, we can show that the ground state is unique.

ar X iv : c on d - m at / 9 51 21 66 v 1 2 4 D ec 1 99 5 ν = 1 / 2 Bilayer Tunnelling

Tunneling of electrons between two ν = 1/2 quantum Hall parallel planes is studied. In order to calculate the physical electron Green's function, the Chern-Simons gauge field formalism is used, both in a perturbative many-body calculation and in a semiclassical calculation. In contrast to recent experiments, no gap in the physical electron density of states is found. A conjecture is made that e...

ar X iv : h ep - l at / 9 51 20 26 v 1 2 1 D ec 1 99 5 1 Υ and J / Ψ spectroscopy using clover fermions in the presence of dynamical quarks

We calculate spin average splittings in the b ¯ b and c¯ c systems using the clover action. We compare static and kinetic masses of heavy-heavy and heavy-light mesons and discuss the consistency of the results.

ar X iv : m at h / 99 07 08 5 v 2 [ m at h . G R ] 1 7 D ec 1 99 9 LOOPS AND SEMIDIRECT PRODUCTS