11,139 research outputs found
A 5-Dimensional Spherical Symmetric Solution in Einstein-Yang-Mills Theory With Gauss-Bonnet Term
We present a numerical solution on a 5-dimensional spherically symmetric
space time, in Einstein-Yang-Mills-Gauss-Bonnet theory using a two point
boundary value routine. It turns out that the Gauss-Bonnet contribution has a
profound influence on the behaviour of the particle-like solution: it increases
the number of nodes of the YM field. When a negative cosmological constant in
incorporated in the model, it turns out that there is no horizon and no
singular behaviour of the model. For positive cosmological constant the model
has singular behaviour.Comment: 7 pages, 6 figure
"Public Employment and Women: The Impact of Argentina’s Jefes Program on Female Heads of Poor Households"
In 2002, Argentina implemented a large-scale public employment program to deal with the latest economic crisis and the ensuing massive unemployment and poverty. The program, known as Plan Jefes, offered part-time work for unemployed heads of households, and yet more than 70 percent of the people who turned up for work were women. The present paper evaluates the operation of this program, its macroeconomic effects, and its impact on program participants. We report findings from our 2005 meetings with policymakers and visits to different project sites. We find that Jefes addresses many important community problems, is well received by participants, and serves the needs of women particularly well. Some of the benefits women report are working in mother-friendly jobs, getting needed training and education, helping the community, and finding dignity and empowerment through work.
Spectrum of TeV Particles in Warped Supersymmetric Grand Unification
In warped supersymmetric grand unification, XY gauge particles appear near
the TeV scale along with Kaluza-Klein towers of the standard model gauge
fields. In spite of this exotic low-energy physics, MSSM gauge coupling
unification is preserved and proton decay is naturally suppressed. In this
paper we study in detail the low-lying mass spectrum of superparticles and GUT
particles in this theory, taking supersymmetry breaking to be localized to the
TeV brane. The masses of the MSSM particles, Kaluza-Klein modes, and XY states
are all determined by two parameters, one which fixes the strength of the
supersymmetry breaking and the other which sets the scale of the infrared
brane. A particularly interesting result is that for relatively strong
supersymmetry breaking, the XY gauginos and the lowest Kaluza-Klein excitations
of the MSSM gauginos may both lie within reach of the LHC, providing the
possibility that the underlying unified gauge symmetry and the enhanced N=2
supersymmetry of the theory will both be revealed.Comment: 29 pages, 5 figure
Shadows of the Planck Scale: The Changing Face of Compactification Geometry
By studying the effects of the shape moduli associated with toroidal
compactifications, we demonstrate that Planck-sized extra dimensions can cast
significant ``shadows'' over low-energy physics. These shadows can greatly
distort our perceptions of the compactification geometry associated with large
extra dimensions, and place a fundamental limit on our ability to probe the
geometry of compactification simply by measuring Kaluza-Klein states. We also
discuss the interpretation of compactification radii and hierarchies in the
context of geometries with non-trivial shape moduli. One of the main results of
this paper is that compactification geometry is effectively renormalized as a
function of energy scale, with ``renormalization group equations'' describing
the ``flow'' of geometric parameters such as compactification radii and shape
angles as functions of energy.Comment: 7 pages, LaTeX, 2 figure
Quasi-Localization of Gravity by Resonant Modes
We examine the behaviour of gravity in brane theories with extra dimensions
in a non-factorizable geometry. We find that for metrics which are
asymptotically flat far from the brane there is a resonant graviton mode at
zero energy. The presence of this resonance ensures quasi-localization of
gravity, whereby at intermediate scales the gravitational laws on the brane are
approximately four dimensional. However, for scales larger than the lifetime of
the graviton resonance the five dimensional laws of gravity will be reproduced
due to the decay of the four dimensional graviton. We also present a simple
classification of the possible types of effective gravity theories on the brane
that can appear for general non-factorizable background theories.Comment: 8 pages, 3 figures included. Requires JHEP.cls. Typos fixed, note and
references added. Added expression for width of resonanc
Gauge Theories in and Fine-Lattice Deconstruction
The logarithmic energy dependence of gauge couplings in AdS_5 emerges almost
automatically when the theory is deconstructed on a coarse lattice. Here we
study the theory away from the coarse-lattice limit. While we cannot
analytically calculate individual KK masses for a fine lattice, we can
calculate the product of all non-zero masses. This allows us to write down the
gauge coupling at low energies for any lattice-spacing and curvature. As
expected, the leading log behaviour is corrected by power-law contributions,
suppressed by the curvature. We then turn to intermediate energies, and discuss
the gauge coupling and the gauge boson profile in perturbation theory around
the coarse-lattice limit.Comment: 17 pages, 1 figure, typos in listing version of abstract correcte
Iodine sorption study on the proposed use of Viton A in a shuttle galley water accumulator
The installation of a Viton A accumulator in the Shuttle galley has been proposed to prevent overpressurization of the hot water supply system. A laboratory study has been conducted to determine if there would be any interaction between the Viton A material and the iodine used to disinfect the water. Coupons of Viton A were exposed for 24 hours to aqueous iodine solutions similar in quality to the Shuttle's potable water. Changes in the iodine residual were monitored to determine the rate of iodine sorption by the coupon. Total organic carbon (TOC) was monitored to determine the rate of desorption of organic materials from the Viton A. The same coupons were then soaked in reagent-grade water for 24 hours, and iodine was monitored to determine the rate of iodine desorption. The coupons were again exposed to iodine solutions for 24 hours and iodine and TOC were monitored. No significant change in the iodine sorption rate was detected between the first and second exposures. A triangle taste test indicated at a 1 percent confidence level that the water exposed to Viton A had a different taste which was less acceptable to the panelists
Current and future graphics requirements for LaRC and proposed future graphics system
The findings of an investigation to assess the current and future graphics requirements of the LaRC researchers with respect to both hardware and software are presented. A graphics system designed to meet these requirements is proposed
Brane in 6D with increasing gravitational trapping potential
A new solution to Einstein equations in (1+5)-spacetime with an embedded
(1+3) brane is given. This solution localizes the zero modes of all kinds of
matter fields and 4-gravity on the (1+3) brane by an increasing, transverse
gravitational potential. This localization occurs despite the fact that the
gravitational potential is not a decreasing exponential, and asymptotically
approaches a finite value rather than zero.Comment: Revised paper. 6 pages, revtex 4. to be published in PR
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