251 research outputs found
Barriers to saving
When the poor succeed in building up a few assets, they often find themselves disqualified from badly needed government programs. Confusing rules about IRAs and 401(k)s plus conflicting state regulations make retirement saving particularly challenging.Saving and investment ; Poverty ; Medicaid ; Social security
A study of chiral symmetry in quenched QCD using the Overlap-Dirac operator
We compute fermionic observables relevant to the study of chiral symmetry in
quenched QCD using the Overlap-Dirac operator for a wide range of the fermion
mass. We use analytical results to disentangle the contribution from exact zero
modes and simplify our numerical computations. Details concerning the numerical
implementation of the Overlap-Dirac operator are presented.Comment: 24 pages revtex with 5 postscript figures included by eps
Topology and chiral symmetry in finite temperature QCD
We investigate the realization of chiral symmetry in the vicinity of the
deconfinement transition in quenched QCD using overlap fermions. Via the index
theorem obeyed by the overlap fermions, we gain insight into the behavior of
topology at finite temperature. We find small eigenvalues, clearly separated
from the bulk of the eigenvalues, and study the properties of their
distribution. We compare the distribution with a model of a dilute gas of
instantons and anti-instantons and find good agreement.Comment: 3 pages with 3 ps figures; to appear in the proceedings of Lattice
'99, Pisa, Italy, June 29 -- July 3, 1999. LATTICE99(topology
A Study of Practical Implementations of the Overlap-Dirac Operator in Four Dimensions
We study three practical implementations of the Overlap-Dirac operator in four dimensions. Two implementations are
based on different representations of as a sum over poles. One
of them is a polar decomposition and the other is an optimal fit to a ratio of
polynomials. The third one is obtained by representing using
Gegenbauer polynomials and is referred to as the fractional inverse method.
After presenting some spectral properties of the Hermitian operator
, we study its spectrum in a smooth SU(2) instanton
background with the aim of comparing the three implementations of . We
also present some results in SU(2) gauge field backgrounds generated at
on an lattice. Chiral properties have been numerically
verified.Comment: 23 pages latex with 9 postscript figures included by epsf. Some
change in referencing and one figure modifie
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