375 research outputs found
Gravitational anomaly and fundamental forces
I present an argument, based on the topology of the universe, why there are
three generations of fermions. The argument implies a preferred gauge group of
SU(5), but with SO(10) representations of the fermions. The breaking pattern
SU(5) to SU(3)xSU(2)xU(1) is preferred over the pattern SU(5) to SU(4)xU(1). On
the basis of the argument one expects an asymmetry in the early universe
microwave data, which might have been detected already.Comment: Contribution to the 2nd School and Workshop on Quantum Gravity and
Quantum Geometry. Corfu, september 13-20 2009. 10 page
Effect of simplicity and attractiveness on route selection for different journey types
This study investigated the effects of six attributes, associated with simplicity or attractiveness, on route preference for three pedestrian journey types (everyday, leisure and tourist). Using stated choice preference experiments with computer generated scenes, participants were asked to choose one of a pair of routes showing either two levels of the same attribute (experiment 1) or different attributes (experiment 2). Contrary to predictions, vegetation was the most influential for both everyday and leisure journeys, and land use ranked much lower than expected in both cases. Turns ranked higher than decision points for everyday journeys as predicted, but the positions of both were lowered by initially unranked attributes. As anticipated, points of interest were most important for tourist trips, with the initially unranked attributes having less influence. This is the first time so many attributes have been compared directly, providing new information about the importance of the attributes for different journeys. © 2014 Springer International Publishing
Towards Solving QCD - The Transverse Zero Modes in Light-Cone Quantization
We formulate QCD in (d+1) dimensions using Dirac's front form with periodic
boundary conditions, that is, within Discretized Light-Cone Quantization. The
formalism is worked out in detail for SU(2) pure glue theory in (2+1)
dimensions which is approximated by restriction to the lowest {\it transverse}
momentum gluons. The dimensionally-reduced theory turns out to be SU(2) gauge
theory coupled to adjoint scalar matter in (1+1) dimensions. The scalar field
is the remnant of the transverse gluon. This field has modes of both non-zero
and zero {\it longitudinal} momentum. We categorize the types of zero modes
that occur into three classes, dynamical, topological, and constrained, each
well known in separate contexts. The equation for the constrained mode is
explicitly worked out. The Gauss law is rather simply resolved to extract
physical, namely color singlet states. The topological gauge mode is treated
according to two alternative scenarios related to the In the one, a spectrum is
found consistent with pure SU(2) gluons in (1+1) dimensions. In the other, the
gauge mode excitations are estimated and their role in the spectrum with
genuine Fock excitations is explored. A color singlet state is given which
satisfies Gauss' law. Its invariant mass is estimated and discussed in the
physical limit.Comment: LaTex document, 26 pages, one figure (obtainable by contacting
authors). To appear in Physical. Review
Unitary Standard Model from Spontaneous Dimensional Reduction and Weak Boson Scattering at the LHC
Spontaneous dimensional reduction (SDR) is a striking phenomenon predicted by
a number of quantum gravity approaches which all indicate that the spacetime
dimensions get reduced at high energies. In this work, we formulate an
effective theory of electroweak interactions based upon the standard model,
incorporating the spontaneous reduction of space-dimensions at TeV scale. The
electroweak gauge symmetry is nonlinearly realized with or without a Higgs
boson. We demonstrate that the SDR ensures good high energy behavior and
predicts unitary weak boson scattering. For a light Higgs boson of mass 125GeV,
the TeV-scale SDR gives a natural solution to the hierarchy problem. Such a
light Higgs boson can have induced anomalous gauge couplings from the TeV-scale
SDR. We find that the corresponding WW scattering cross sections become unitary
at TeV scale, but exhibit different behaviors from that of the 4d standard
model. These can be discriminated by the WW scattering experiments at the LHC.Comment: 38pp, Eur.Phys.J.(in Press); extended discussions for testing non-SM
Higgs boson(125GeV) via WW scattering; minor clarifications added; references
added; a concise companion is given in the short PLB letter arXiv:1301.457
Comparison of immune response to lipopolysaccharide of rabbit does selected for litter size at weaning or founded for reproductive longevity
To evaluate differences in maternal lines to the immune response of reproductive rabbit does, a total of 64 animals of two different lines: (1) founded for hyper-longevity and litter size criteria (LP) and (2) selected for litter size at weaning (V) were used. Females were subjected to three different reproductive efforts: post-partum (PP) mating at first lactation and 9 kits during the second; post-weaning (PW) mating at first lactation and 9 kits during the second; and PW mating at first lactation and 5 kits during the second. At second weaning (30 days PP), an acute response was induced by intravenous infusion of lipopolysaccharide (LPS). LP females seemed to be lower affected during the hyper-acute phase than V females, showing lower plasma glucose content at 1.5 h post infusion (pi) and rectal temperature at 6 h pi; and showed higher ulterior immune response, with higher levels of C-reactive protein at 48 h pi and haptoglobin in plasma from 24 h pi. Survival test conferred a higher risk of culling for V than for LP females during the first hours after challenge. These results may suggest that, regarding immune response to LPS challenge, foundation by hyper-longevity productive criteria lead to obtain a more robust population of rabbit does, characterized by improved response ability. (C) 2013 Elsevier Ltd. All rights reserved.This study has been supported by the Interministerial Commission for Science and Technology (CICYT) from the Spanish Government. Grants Number: AGL2011-30170-C02-01; AGL2011-30170-C02-02), is gratefully acknowledged.Ferrian, S.; Blas Ferrer, E.; Larsen, T.; Sánchez Serrano, JP.; Friggens, NC.; Corpa, JM.; Baselga Izquierdo, M.... (2013). Comparison of immune response to lipopolysaccharide of rabbit does selected for litter size at weaning or founded for reproductive longevity. Research in Veterinary Science. 94(3):518-525. doi:10.1016/j.rvsc.2013.01.008S51852594
A Comparison of Ballistic and Nonballistic Lower-Body Resistance Exercise and the Methods Used to Identify Their Positive Lifting Phases
Remarks on Dirac-like Monopole, Maxwell and Maxwell-Chern-Simons Electrodynamics in D=(2+1)
Classical Maxwell and Maxwell-Chern-Simons (MCS) Electrodynamics in (2+1)D
are studied in some details. General expressions for the potential and fields
are obtained for both models, and some particular cases are explicitly solved.
Conceptual and technical difficulties arise, however, for accelerated charges.
The propagation of electromagnetic signals is also studied and their
reverberation is worked out and discussed. Furthermore, we show that a
Dirac-like monopole yields a (static) tangential electric field. We also
discuss some classical and quantum consequences of the field created by such a
monopole when acting upon an usual electric charge. In particular, we show that
at large distances, the dynamics of one single charged particle under the
action of such a potential and a constant (external) magnetic field as well,
reduces to that of one central harmonic oscillator, presenting, however, an
interesting angular sector which admits energy-eigenvalues. Among other
peculiarities, both sectors, the radial and the angular one, present
non-vanishing energy-eigenvalues for their lowest level. Moreover, those
associated to the angle are shown to respond to discrete shifts of such a
variable. We also raise the question whether the formation of bound states is
possible in the system.Comment: 17 pages, 2 figures. To appear in Phys. Rev.
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