3,596 research outputs found
A Covariant Information-Density Cutoff in Curved Space-Time
In information theory, the link between continuous information and discrete
information is established through well-known sampling theorems. Sampling
theory explains, for example, how frequency-filtered music signals are
reconstructible perfectly from discrete samples. In this Letter, sampling
theory is generalized to pseudo-Riemannian manifolds. This provides a new set
of mathematical tools for the study of space-time at the Planck scale: theories
formulated on a differentiable space-time manifold can be completely equivalent
to lattice theories. There is a close connection to generalized uncertainty
relations which have appeared in string theory and other studies of quantum
gravity.Comment: 4 pages, RevTe
Abelian Monopole and Center Vortex Views at the Multi-Instanton Gas
We consider full non-Abelian, Abelian and center projected lattice field
configurations built up from random instanton gas configurations in the
continuum. We study the instanton contribution to the force with
respect to ({\it i}) instanton density dependence, ({\it ii}) Casimir scaling
and ({\it iii}) whether various versions of Abelian dominance hold. We check
that the dilute gas formulation for the interaction potential gives an reliable
approximation only for densities small compared to the phenomenological value.
We find that Casimir scaling does not hold, confirming earlier statements in
the literature. We show that the lattice used to discretize the instanton gas
configurations has to be sufficiently coarse ( compared
with the instanton size ) such that maximal Abelian gauge
projection and center projection as well as the monopole gas contribution to
the force reproduce the non-Abelian instanton-mediated force in the
intermediate range of linear quasi-confinement. We demonstrate that monopole
clustering also depends critically on the discretization scale confirming
earlier findings based on monopole blocking.Comment: 21 pages, 22 Postscript figure
Monte Carlo simulation of SU(2) Yang-Mills theory with light gluinos
In a numerical Monte Carlo simulation of SU(2) Yang-Mills theory with light
dynamical gluinos the low energy features of the dynamics as confinement and
bound state mass spectrum are investigated. The motivation is supersymmetry at
vanishing gluino mass. The performance of the applied two-step multi-bosonic
dynamical fermion algorithm is discussed.Comment: latex, 48 pages, 16 figures with epsfi
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