Random Walkers with Shrinking Steps in d-Dimensions and Their Long Term Memory

We study, in d-dimensions, the random walker with geometrically shrinking step sizes at each hop. We emphasize the integrated quantities such as expectation values, cumulants and moments rather than a direct study of the probability distribution. We develop a 1/d expansion technique and study various correlations of the first step to the position as ti me goes to infinity. We also show and substantiate with a study of the cumulants that to order 1/d the system admits a continuum counterpart equation which can be obtained with a generalization of the ordinary technique to obtain the continuum limit. We also advocate that this continuum counterpart equation, which is nothing but the ordinary diffusion equation with a diffusion constant decaying exponentially in continuous time, captures all the qualitative aspects of t he discrete system and is often a good starting point for quantitative approximations

Friedmann Equation for Brans Dicke Cosmology

In the context of Brans-Dicke scalar tensor theory of gravitation, the cosmological Friedmann equation which relates the expansion rate $H$ of the universe to the various fractions of energy density is analyzed rigorously. It is shown that Brans-Dicke scalar tensor theory of gravitation brings a negligible correction to the matter density component of Friedmann equation. Besides, in addition to $\Omega_{\Lambda}$ and $\Omega_{M}$ in standard Einstein cosmology, another density parameter, $\Omega_{_{\Delta}}$, is expected by the theory. This implies that if $\Omega_{_{\Delta}}$ is found to be nonzero, data will favor this model instead of the standard Einstein cosmological model with cosmological constant and will enable more accurate predictions for the rate of change of Newtonian gravitational constant in the future.Comment: minor reference change

Brane World Cosmology In Jordan-Brans-Dicke Theory

We consider the embedding of 3+1 dimensional cosmology in 4+1 dimensional Jordan-Brans-Dicke theory. We show that exponentially growing and power law scale factors are implied. Whereas the 4+1 dimensional scalar field is approximately constant for each, the effective 3+1 dimensional scalar field is constant for exponentially growing scale factor and time dependent for power law scale factor.Comment: 11 page

Static Cylindrical Matter Shells

Static cylindrical shells composed of massive particles arising from matching of two different Levi-Civita space-times are studied for the shell satisfying either isotropic or anisotropic equation of state. We find that these solutions satisfy the energy conditions for certain ranges of the parameters.Comment: 9 pages, 3 figures, Latex; Final version, To appear in General Relativity and Gravitatio

The ATLAS muon micromegas R&D project: towards large-size chambers for the s-LHC

Detectors based on the bulk-Micromegas technology exhibit position resolution better than 100 m m at counting rates of up to several tens of kHz/cm(2), along with trigger capabilities. These characteristics, combined with the detector's mechanical robustness and the possibility for cost-effective industrial production, makes them a promising candidate for the ATLAS Muon Spectrometer upgrade in a future luminosity enhancement of the LHC. The R&D project status will be presented together with the obtained results in the effort to define the baseline system specifications

Over restrictive elimination of foods in children with foodallergy

Background. Previous studies demonstrated critical deficits in diagnosis and management of childhood foodallergy (FA), and recent developments in FA research support adopting a proactive approach in FA management.Our objective was to describe FA knowledge and management patterns of pediatricians.Method. We applied a 24-item survey to 170 general pediatricians, pediatric allergists and pediatricgastroenterologists practicing in Turkey.Results. Some IgE-mediated symptoms of FA such as cough, urticaria, wheezing and anaphylaxis were falselyrecognized as symptoms of non-IgE-mediated FA by 30%, 29%, 25% and 19% of the participants, respectively.By contrast, 50% of the participants falsely recognized bloody stool, a finding of IgE-mediated FA. Mostfrequently and least frequently used diagnostic tools were specific IgE (30.5%) and oral food challenge test(1.7%), respectively. Maternal diet restrictions and infant diet restrictions were advised by 82% and 82%,respectively. Percentages of physicians eliminating only 1 food were 21%, 19%; 2 foods were 15%, 11%; 3 foodswere 7%, 8%; 4-5 foods were 8%, 11%; 5 to 10 foods were 21%, 26%; and >10 foods were 28%, 25% from thematernal and infant diet, respectively. Cow’s milk, cheese, butter, yoghurt, baked milk products and hen’s eggwere the most commonly restricted items.Conclusion. Overall, FA knowledge of pediatricians was fair. Pediatricians utilize an overly restrictive approachwhen advising diet eliminations in FA. Recent developments favor a more proactive approach to induce immunetolerance and need to be encouraged in pediatric clinical practice. Future educational efforts should focus onemphasizing the deleterious effects of injudicious and extensive eliminations

Discrete quantum model of the harmonic oscillator

We construct a new model of the quantum oscillator, whose energy spectrum is equally-spaced and lower-bounded, whereas the spectra of position and momentum are a denumerable non-degenerate set of points in [-1,1] that depends on the deformation parameter q from (0,1). We provide its explicit wavefunctions, both in position and momentum representations, in terms of the discrete q-Hermite polynomials. We build a Hilbert space with a unique measure, where an analogue of the fractional Fourier transform is defined in order to govern the time evolution of this discrete oscillator. In the limit q to 1, one recovers the ordinary quantum harmonic oscillator.Comment: 21 page

Higher Dimensional Cylindrical or Kasner Type Electrovacuum Solutions

We consider a D dimensional Kasner type diagonal spacetime where metric functions depend only on a single coordinate and electromagnetic field shares the symmetries of spacetime. These solutions can describe static cylindrical or cosmological Einstein-Maxwell vacuum spacetimes. We mainly focus on electrovacuum solutions and four different types of solutions are obtained in which one of them has no four dimensional counterpart. We also consider the properties of the general solution corresponding to the exterior field of a charged line mass and discuss its several properties. Although it resembles the same form with four dimensional one, there is a difference on the range of the solutions for fixed signs of the parameters. General magnetic field vacuum solution are also briefly discussed, which reduces to Bonnor-Melvin magnetic universe for a special choice of the parameters. The Kasner forms of the general solution are also presented for the cylindrical or cosmological cases.Comment: 16 pages, Revtex. Text and references are extended, Published versio

Consequences of the extra SM families on the Higgs boson production at Tevatron and LHC

The latest electroweak precission data allow the existence of additional chiral generations in the standard model. We study the influence of extra generations on the production of SM Higgs boson at hadron colliders. Due to the enhancement of the gluon fusion channel, the ``golden mode'' becomes more promising even at upgraded Tevatron. Furthermore, the formation of the fourth family quarkonia with the subsequent $\eta_{4}\to ZH$ decay introduces additional tool for the investigation of the Higgs boson properties.Comment: 12 pages, 6 figures, 2 table