6,946 research outputs found
Combinatorics of lattice paths with and without spikes
We derive a series of results on random walks on a d-dimensional hypercubic
lattice (lattice paths). We introduce the notions of terse and simple paths
corresponding to the path having no backtracking parts (spikes). These paths
label equivalence classes which allow a rearrangement of the sum over paths.
The basic combinatorial quantities of this construction are given. These
formulas are useful when performing strong coupling (hopping parameter)
expansions of lattice models. Some applications are described.Comment: Latex. 25 page
Large reduction with the Twisted Eguchi-Kawai model
We examine the breaking of symmetry recently reported for the Twisted
Eguchi-Kawai model (TEK). We analyse the origin of this behaviour and propose
simple modifications of twist and lattice action that could avoid the problem.
Our results show no sign of symmetry breaking and allow us to obtain values of
the large infinite volume string tension in agreement with extrapolations
from results based upon straightforward methods.Comment: latex file 14 pages, 4 figure
Calorons on the lattice - a new perspective
We discuss the manifestation of instanton and monopole solutions on a
periodic lattice at finite temperature and their relation to the infinite
volume analytic caloron solutions with asymptotic non-trivial Polyakov loops.
As a tool we use improved cooling and twisted boundary conditions. Typically we
find 2Q lumps for topological charge Q. These lumps are BPS monopoles.Comment: Latex. 16 pages, 9 figure
Anomalous magnetic and weak magnetic dipole moments of the lepton in the simplest little Higgs model
We obtain analytical expressions, both in terms of parametric integrals and
Passarino-Veltman scalar functions, for the one-loop contributions to the
anomalous weak magnetic dipole moment (AWMDM) of a charged lepton in the
framework of the simplest little Higgs model (SLHM). Our results are general
and can be useful to compute the weak properties of a charged lepton in other
extensions of the standard model (SM). As a by-product we obtain generic
contributions to the anomalous magnetic dipole moment (AMDM), which agree with
previous results. We then study numerically the potential contributions from
this model to the lepton AMDM and AWMDM for values of the parameter
space consistent with current experimental data. It is found that they depend
mainly on the energy scale at which the global symmetry is broken and the
parameter, whereas there is little sensitivity to a mild change in
the values of other parameters of the model. While the AMDM is of the
order of , the real (imaginary) part of its AWMDM is of the order of
(). These values seem to be out of the reach of the
expected experimental sensitivity of future experiments.Comment: 23 pages, 11 figures, new analysis and References adde
Non-Abelian Vortices on the Torus
We study periodic arrays of non-Abelian vortices in an
gauge theory with flavors of fundamental matter multiplets. We carefully
discuss the corresponding twisted boundary conditions on the torus and propose
an ansatz to solve the first order Bogomolnyi equations which we find by
looking to a bound of the energy. We solve the equations numerically and
construct explicit vortex solutions
Recent results on self-dual configurations on the torus
We review the recent progress on our understanding of self-dual SU(N)
Yang-Mills configurations on the torus.Comment: Latex 3 pages, 1 figure. Contribution to the Lat99 Proceeding
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