Spectral density analysis of the chiral transition in nf=4 finite temperature QCD

We apply the spectral density reweighting technique to the analysis of the chiral phase transition in finite-temperature lattice quantum chromodynamics (QCD) with four flavors of dynamical staggered fermions and m_qa=0.025. Our simulations were performed using the hybrid Monte Carlo method for L_tL³ lattices with L_t=4 and L=6, 8 and 10. We calculate partition function zeros, as well as the maxima of the specific heat and of the susceptibilities for the Polyakov loop and for the chiral condensate. A finite size scaling analysis of these data leads to preliminary results for the critical coupling β_c, for the critical exponent ν, for the latent heat, and for the jumps in the Polyakov loop and in the chiral condensate.     

Influence of the Measurement Volume on the Phase Error in Phase Doppler Anemometry. Part 1: Reflective mode operation

In phase Doppler anemometry (PDA), phase difference errors are caused by the Gaussian intensity distribution of the laser beam and the curvature of the phase fronts outside of the beam waist. This results in erroneous particle sizes. Based on a physical analysis by geometrical optics [1], this phase difference error is evaluated for reflected mode operation (Part I) and for refracted mode operation (Part II). By varying the particle trajectories statistically, the error in determining the particle size and the mass flow can be simulated. By the method described the error in the measured phase difference can easily be estimated.     

A condition for zero entropy

Criteria for a homeomorphism of a compact metric space to have zero topological entropy are obtained. These are applied to show that minimal distal and POD flows have zero entropy. These notions are also relativized, and it is shown that entropy is preserved by the extensions they define.     

Multicanonical recursions

The problem of calculating multicanonical parameters recursively is discussed. I describe in detail a computational implementation which has worked reasonably well in practice.     

On an entry of ramanujan concerning divergent series

A vague entry of Ramanujan concerning nearly equal terms of two divergent series is put into a precise form.