583 research outputs found
Some results and problems for anisotropic random walks on the plane
This is an expository paper on the asymptotic results concerning path
behaviour of the anisotropic random walk on the two-dimensional square lattice
Z^2. In recent years Mikl\'os and the authors of the present paper investigated
the properties of this random walk concerning strong approximations, local
times and range. We give a survey of these results together with some further
problems.Comment: 20 page
New Confining N=1 Supersymmetric Gauge Theories
We examine N=1 supersymmetric gauge theories which confine in the presence of
a tree-level superpotential. We show the confining spectra which satisfy the 't
Hooft anomaly matching conditions and give a simple method to find the
confining superpotential. Using this method we fix the confining
superpotentials in the simplest cases, and show how these superpotentials are
generated by multi-instanton effects in the dual theory. These new type of
confining theories may be useful for model building, since the size of the
matter content is not restricted by an index constraint. Therefore, one expects
that a large variety of new confining spectra can be obtained using such
models.Comment: 26 pages, LaTe
Gauge-Higgs Unification in Orbifold Models
Six-dimensional orbifold models where the Higgs field is identified with some
internal component of a gauge field are considered. We classify all possible
T^2/Z_N orbifold constructions based on a SU(3) electroweak gauge symmetry.
Depending on the orbifold twist, models with two, one or zero Higgs doublets
can be obtained. Models with one Higgs doublet are particularly interesting
because they lead to a prediction for the Higgs mass, which is twice the W
boson mass at leading order: m_H=2 m_W. The electroweak scale is quadratically
sensitive to the cut-off, but only through very specific localized operators.
We study in detail the structure of these operators at one loop, and identify a
class of models where they do not destabilize the electroweak scale at the
leading order. This provides a very promising framework to construct realistic
and predictive models of electroweak symmetry breaking.Comment: 27 pages, uses axodraw.sty; v2: version to appear in JHE
The shortest cut in brane cosmology
We consider brane cosmology studying the shortest null path on the brane for
photons, and in the bulk for gravitons. We derive the differential equation for
the shortest path in the bulk for a 1+4 cosmological metric. The time cost and
the redshifts for photons and gravitons after traveling their respective path
are compared. We consider some numerical solutions of the shortest path
equation, and show that there is no shortest path in the bulk for the
Randall-Sundrum vacuum brane solution, the linear cosmological solution of
Bin\'etruy, et al for , and for some expanding brane
universes.Comment: 20 pages, 7 figure
Comment on 4D Lorentz invariance violations in the brane-world
The brane-world scenario offers the possibility for signals to travel outside
our visible universe and reenter it. We find the condition for a signal emitted
from the brane to return to the brane. We study the propagation of such signals
and show that, as seen by a 4D observer, these signals arrive earlier than
light traveling along the brane. We also study the horizon problem and find
that, while the bulk signals can travel far enough to homogenize the visible
universe, it is unlikely that they have a significant effect since they are
redshifted in the gravitational field of the bulk black hole.Comment: 21 pages, 6 figures, REVTEX, New section adde
N=1 Supersymmetric Product Group Theories in the Coulomb Phase
We study the low-energy behavior of N=1 supersymmetric gauge theories with
product gauge groups SU(N)^M and M chiral superfields transforming in the
fundamental representation of two of the SU(N) factors. These theories are in
the Coulomb phase with an unbroken U(1)^(N-1) gauge group. For N >= 3, M >= 3
the theories are chiral. The low-energy gauge kinetic functions can be obtained
from hyperelliptic curves which we derive by considering various limits of the
theories. We present several consistency checks of the curves including
confinement through the addition of mass perturbations and other limits.Comment: 22 pages, LaTeX, minor changes. Eqs. (20) and (42) correcte
Quality of functional movement patterns and injury examination in elite-level male professional football players
The purpose of this study is to examine the quality of functional movement patterns among one of Hungary’s first league soccer clubs, where the elite male football players (N = 20) utilize the well-established Functional Movement Screen™ (FMS) system; a comprehensive functional program designed to determine and identify the quality of movement and the greatest risk factors for non-contact injuries. Furthermore, an additional purpose of this program is to examine injuries over the course of 6 competitive months. Focusing on the mechanisms of injuries and their causes in the lower extremities during this period is one of the key objectives. Over the course of 6 months we found significant differences between ankle injuries and the FMS Hurdle Step exercise (p < 0.05), and the FMS Deep Squat exercise and knee and hip injuries (p < 0.05). The FMS pre-screening system found lower limb asymmetry present in 40% of the participants. The authors believe that the importance of preventative measures and structural sport specific pre-screening cannot be overemphasized, and that there is a growing need for further transparent research in this field in order to be more effective with regard to programs dedicated to injury prevention and the enhancement players’ physical performance
Seiberg-Witten Description of the Deconstructed 6D (0,2) Theory
It has recently been suggested that, in a large N limit, a particular four
dimensional gauge theory is indistinguishable from the six dimensional CFT with
(0,2) supersymmetry compactified on a torus. We give further evidence for this
correspondence by studying the Seiberg-Witten curve for the "deconstructed"
theory and demonstrating that along the reduced Coulomb branch of moduli space
(on the intersection of the Higgs and Coulomb branches) it describes the low
energy physics on a stack of M5-branes on a torus, which is the (0,2) theory on
a torus as claimed. The M-theory construction helps to clarify the enhancement
of supersymmetry in the deconstructed theory at low energies, and demonstrates
its stability to radiative and instanton corrections. We demonstrate the role
of the theta vacuum in the deconstructed theory. We point out that by varying
the theta parameters and gauge couplings in the deconstructed theory, the
complex structure of the torus can be chosen arbitrarily, and the torus is not
metrically S^1 x S^1 in general.Comment: 13 pages, 2 figure
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