arXiv subjects

Chulwoo Jung

Publications and source records attributed to Chulwoo Jung.

79 records · Page 5Linked to original sources

arXiv2000

Residual Chiral Symmetry Breaking in Domain-Wall Fermions

We study the effective quark mass induced by the finite separation of the domain walls in the domain-wall formulation of chiral fermion as the function of the size of the fifth dimension ($L_s$), the gauge coupling $β$ and the physical volume $V$. We measure the mass by calculating the small eigenvalues of the hermitian domain-wall Dirac operator ($H_{\rm DWF}(m_0))$ in the topologically-nontrivial quenched SU(3) gauge configurations. We find that the induced quark mass is nearly independent of the physical volume, decays exponentially as a function of $L_s$, and has a strong dependence on the size of quantum fluctuations controlled by $β$. The effect of the choice of the lattice gluon action is also studied.

hep-lat↗

arXiv2000

Domain-Wall Induced Quark Masses in Topologically-Nontrivial Background

In the domain-wall formulation of chiral fermion, the finite separation between domain-walls ($L_s$) induces an effective quark mass ($m_{\rm eff}$) which complicates the chiral limit. In this work, we study the size of the effective mass as the function of $L_s$ and the domain-wall height $m_0$ by calculating the smallest eigenvalue of the hermitian domain-wall Dirac operator in the topologically-nontrivial background fields. We find that, just like in the free case, $m_{\rm eff}$ decreases exponentially in $L_s$ with a rate depending on $m_0$. However, quantum fluctuations amplify the wall effects significantly. Our numerical result is consistent with a previous study of the effective mass from the Gell-Mann-Oakes-Renner relation.

hep-lat↗

arXiv1998

Status of the QCDSP project

We describe the completed 8,192-node, 0.4Tflops machine at Columbia as well as the 12,288-node, 0.6Tflops machine assembled at the RIKEN Brookhaven Research Center. Present performance as well as our experience in commissioning these large machines is presented. We outline our on-going physics program and explain how the configuration of the machine is varied to support a wide range of lattice QCD problems, requiring a variety of machine sizes. Finally a brief discussion is given of future prospects for large-scale lattice QCD machines.

hep-lat↗

arXiv1997

Monopole-antimonopole condensation in the interpolating Georgi-Glashow model

We study the three dimensional Georgi-Glashow model (which interpolates smoothly between pure U(1) and SU(2) limits) using a constrained cooling which preserves 't Hooft-Polyakov monopoles. We find that the monopole-antimonopole condensation gives an area law for the Wilson loops. The monopole contribution to the string tension is close to the Monte Carlo value in the intermediate region.

hep-lat↗

arXiv1997

QCDSP - A status report

The QCDSP machine at Columbia University has grown to 2,048 nodes achieving a peak speed of 100 Gigaflops. Software for quenched and Hybrid Monte Carlo (HMC) evolution schemes has been developed for staggered fermions, with support for Wilson and clover fermions under development. We provide an overview of the runtime environment, the current status of the QCDSP construction program and preliminary results not presented elsewhere in these proceedings.

hep-lat↗

arXiv1996

Relating U(1) monopole configurations to SU(2) saddle-point configurations

We have studied field configurations of the 3-dimensional Georgi-Glashow model which interpolate between the $U(1)$ and the $SU(2)$ limits. In the intermediate region, these configurations contain 't-Hooft--Polyakov monopoles. We use cooling and extremization to find these configurations and investigate their evolution as we adiabatically move towards the $U(1)$ and the $SU(2)$ limits. We also evolve an $SU(2)$ saddle point solution towards the $U(1)$ limit to see the relation between the unstable solutions in the $SU(2)$ theory and the stable ones in the $U(1)$ theory.

hep-lat↗

arXiv1995

Analysis of saddle-point configurations in 3-dimensional SU(2) gauge theory

We discuss the properties of a class of saddle point solutions in SU(2) in three dimensions (SU$(2)_3$), exhibiting localized peaks in the action. These configurations are generated by deterministic cooling and extremizing algorithms from analytic configurations. They share some characteristics with cooled and extremized Monte Carlo generated lattices. We have investigated physical behavior such as the string tension by averaging over this class of saddle point configurations. We have also measured the eigenvalues for harmonic fluctuations around these configurations.

hep-lat↗