Thu·Jul 25, 2002Thursday·July 25, 2002

1. 01*

   Partial-Global Stochastic Metropolis Update for Dynamical Smeared Link Fermions

   Andrei Alexandru🇺🇸 · Anna Hasenfratz🇺🇸

   We performed dynamical simulations with HYP smeared staggered fermions using the recently proposed partial-global stochastic Metropolis algorithm with fermion matrix reduction and determinant breakup improvements. In this paper we discuss our choice of the action parameters and study the autocorrelation time both with four and two fermionic flavors at different quark mass values on approximately 10 fm^4 lattices. We find that the update is especially efficient with two flavors making simulations on larger volumes feasible.

   hep-latPRD(2002)·27 citations
2. 02*

   A new proposal for the fermion doubling problem. II. Improving the operators for finite lattices

   John P. Costella🇦🇺

   In a previous paper I showed how the ideal SLAC derivative and second-derivative operators for an infinite lattice can be obtained in simple closed form in position space, and implemented very efficiently in a stochastic fashion for practical calculations on finite lattices. In this second paper I show how the small (order 1/N) errors introduced by truncating the operators to a finite lattice may be removed by a small adjustment of coefficients, without incurring any additional computational cost. The derivation of these results is again presented in a simple, pedagogical fashion.

   hep-lat7 citations
3. 03*

   The Information Geometry of the Ising Model on Planar Random Graphs

   W. Janke🇩🇪 · D.A. Johnston🇬🇧 · Ranasinghe P. K. C. Malmini🇱🇰

   It has been suggested that an information geometric view of statistical mechanics in which a metric is introduced onto the space of parameters provides an interesting alternative characterisation of the phase structure, particularly in the case where there are two such parameters -- such as the Ising model with inverse temperature $\beta$ and external field $h$. In various two parameter calculable models the scalar curvature $\mathcal{R}$ of the information metric has been found to diverge at the phase transition point ${\beta }_c$ and a plausible scaling relation postulated: $\mathcal{R}\sim |\beta -{\beta }_c{|}^{\alpha -2}$. For spin models the necessity of calculating in non-zero field has limited analytic consideration to 1D, mean-field and Bethe lattice Ising models. In this letter we use the solution in field of the Ising model on an ensemble of planar random graphs (where $\alpha =-1,\beta =1/2,\gamma =2$) to evaluate the scaling behaviour of the scalar curvature, and find $\mathcal{R}\sim |\beta -{\beta }_c{|}^{-2}$. The apparent discrepancy is traced back to the effect of a negative $\alpha$.

   ↳ cond-mat.stat-mechhep-latPRE(2002)·21 citations
4. 04*

   Finite-temperature behavior of the (2+1)D Georgi-Glashow model with and without quarks

   Dmitri Antonov (INFN, Pisa and Pisa University)🇮🇹

   (2+1)-dimensional Georgi-Glashow model and its SU(N)-generalization are explored at nonzero temperatures and in the regime when the Higgs boson is not infinitely heavy. The finiteness of the Higgs-boson mass leads to various novel effects. Those include the appearance of two separate phase transitions and of the upper bound on the parameter of the weak-coupling approximation, necessary to maintain the stochasticity of the Higgs vacuum. The modification of the finite-temperature behavior of the model emerging due to the introduction of massless quarks is also discussed.

   ↳ hep-thcond-mathep-lathep-ph2 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.