The calculation of critical amplitudes in SU(2) lattice gauge theory
We calculate the critical amplitudes of the Polyakov loop and its susceptibility at the deconfinement transition of (3 + 1)-dimensional SU(2) gauge theory. To this end we study the corrections due to irrelevant exponents in the scaling functions. As a guiding line for determining the critical amplitudes we use envelope equations which we derive from the finite site scaling formulae of the observables. We have produced new high precision data on N-sigma(3) x 4 lattices for N-sigma = 12, 18, 26 and 36, With these data we find different corrections to the asymptotic scaling behaviour above and below the transition. Our result for the universal ratio of the susceptibility amplitudes is C+/C- = 4.72(11) and thus in excellent agreement with a recent measurement for the 3d Ising model. (C) 1999 Published by Elsevier Science B.V.
The spectrum of massive excitations of 3d 3-state Potts model and universality
Abstract We consider the mass spectrum of the 3 d 3-state Potts model in the broken phase (a) near the second order Ising critical point in the temperature–magnetic field plane and (b) near the weakly first order transition point at zero magnetic field. In the case (a), we compare the mass spectrum with the prediction from universality of mass ratios in the 3 d Ising class; in the case (b), we determine a mass ratio to be compared with the corresponding one in the spectrum of screening masses of the ( 3 + 1 ) d SU ( 3 ) pure gauge theory at finite temperature in the deconfined phase near the transition. The agreement in the comparison in the case (a) would represent a non-trivial test of validity of the conjecture of spectrum universality. A positive answer to the comparison in the case (b) would suggest the possibility to extend this conjecture to weakly first order phase transitions.
Integration of Optically Generated Impulse Radio UWB Signals Into Baseband WDM-PON
We propose a compact integration system to simultaneously provide wireline and wireless [baseband and ultra-wideband (UWB)] services to end-users in a wavelength-division-multiplexed-passive optical network (WDM-PON). A 1-Gb/s UWB signal is optically generated and shares the same wavelength with the baseband signal. Error-free performance was achieved after 23-km single-mode-fiber (SMF) transmission for both signals and additional 0.4-m wireless transmission for the UWB signal. The low complexity and high spectrum efficiency of this system makes it attractive for deployment of in wireline/wireless converged gigabit optical access networks.