Thermodynamic analysis of topological black holes in Gauss-Bonnet gravity with nonlinear source

Employing two classes of nonlinear electrodynamics, we obtain topological black hole solutions of Gauss-Bonnet gravity. We investigate geometric properties of the solutions and find that there is an intrinsic singularity at the origin. We investigate the thermodynamic properties of the asymptotically flat black holes and also asymptotically adS solutions. Using suitable local transformation, we generalize static horizon-flat solutions to rotating ones. We discuss their conserved and thermodynamic quantities as well as the first law of thermodynamics. Finally, we calculate the heat capacity of the solutions to obtain a constraint on the horizon radius of stable solutions.Comment: accepted in Eur. Phys. J. C (DOI: 10.1140/epjc/s10052-014-3079-9

Global fits to b -> s ll data and signs for lepton non-universality

There are some slight tensions with the SM predictions within the latest LHCb measurements. Besides the known anomaly in one angular observable of the rare decay B -> K* mu+ mu-, another small discrepancy recently occurred. The ratio R_K = BR(B+ -> K+ mu+ mu-) / BR(B+ -> K+ e+ e-) in the low-q^2 region has been measured by LHCb showing a 2.6 sigma deviation from the SM prediction. In contrast to the anomaly in the rare decay B -> K* mu+ mu- which is affected by power corrections, the ratio R_K is theoretically rather clean. We analyse all the b -> s ll data with global fits and in particular explore the possibility of breaking of lepton universality. Possible cross-checks with an analysis of the inclusive B -> X_s l+ l- decay are also explored.Comment: 15 pages, 11 figures. v2: references added, to appear in JHE

On the anomalies in the latest LHCb data

Depending on the assumptions on the power corrections to the exclusive b -> s l+ l- decays, the latest data of the LHCb collaboration - based on the 3 fb^-1 data set and on two different experimental analysis methods - still shows some tensions with the SM predictions. We present a detailed analysis of the theoretical inputs and various global fits to all the available b -> s l+ l- data. This constitutes the first global analysis of the new data of the LHCb collaboration based on the hypothesis that these tensions can be at least partially explained by new physics contributions. In our model-independent analysis we present one-, two-, four-, and also five-dimensional global fits in the space of Wilson coefficients to all available b -> s l+ l- data. We also compare the two different experimental LHCb analyses of the angular observables in B -> K* mu+ mu-. We explicitly analyse the dependence of our results on the assumptions about power corrections, but also on the errors present in the form factor calculations. Moreover, based on our new global fits we present predictions for ratios of observables which may show a sign of lepton non-universality. Their measurements would crosscheck the LHCb result on the ratio R_K = BR(B+ -> K+ mu+ mu-) / BR(B+ -> K+ e+ e-) in the low-q^2 region which deviates from the SM prediction by 2.6 sigma.Comment: 41 pages, 24 figures. v2: references and comment on 1006.4945 [hep-ph] adde

Noether gauge symmetry approach applying for the non-minimally coupled gravity to the Maxwell field

Taking the Noether gauge symmetry approach into account, we find spherically symmetric static black hole solutions of the non-minimal gauge-gravity Lagrangian of the $\mathcal{R}^\beta F^2$ model. At first, we consider a system of differential equations for the general non-minimal couplings of $Y(\mathcal{R})F^2$ type, and then, we regard a particular $\mathcal{R}^\beta F^2$ non-minimal model to find the exact black hole solution and analyze its symmetries. As the next step, we calculate the thermodynamical quantities of the black hole and study its interesting behavior. Besides, we address thermal stability and examine the possibility of the van der Waals-like phase transition.Comment: 17 pages, 20 figure

Effect of sports vision exercise on visual perception and reading performance in 7- to 10-year-old developmental dyslexic children

The presented study was aimed at identifying for the first time the influence of sports vision exercises on fundamental motor skills and cognitive skills of 7- to 10-year-old developmental dyslexic Persian children. A pretest - posttest quasi-experimental study was conducted. The statistical population of this study was 7- to 10-year-old dyslexic children referring to two centres of learning disorder in the city of Isfahan. Twenty two of these children were selected using available and purposive sampling from the statistical population and were randomly assigned into two groups of experimental and control. The former (experimental group) participated in sports vision exercise courses for 12 weeks (3 one hr sessions per week) and the latter (control group) continued their routine daily activities during the exercise. Before the beginning and at the end of the exercise, Gardner’s test of visual perception test - revised and Dehkhoda’s reading skills test was administered to both groups. The results showed that the sports vision exercises increases motor skills, visual perceptual skills and reading skills in developmental dyslexic children. Based on the results of the presented study it was concluded that sports vision exercises can be used for fundamental and cognitive skills of developmental dyslexic children

A Comprehensive Review of Geometrical Thermodynamics: From Fluctuations to Black Holes

This paper presents a comprehensive review of geometrical thermodynamics, which employs geometric concepts to study the thermodynamic properties of physical systems. The review covers key topics such as thermodynamic fluctuation theory, proposed thermodynamic metrics in various coordinate systems, and thermodynamic curvature. Additionally, the paper discusses the geometrical approach to black hole thermodynamics and provides an overview of recent research in this field.Comment: 43 pages, 7 figures, and 3 tables, an updated versio

Epidemiology of nosocomial infections in pediatric patients in an Iranian referral hospital

Nosocomial infections (NI) are important causes of morbid- ity and mortality in pediatric hospitals. Different surveillance methods for detecting hospital-acquired infection have been developed. The selection of which varies according to specific surveillance objectives and the resources are available. The aim of this study was to determine the epidemiology of noso- comial infections in medical wards of a tertiary-levels teaching pediatric hospital in Tehran, Iran. We performed a prospective cross-sectional study and NI was identified by daily review of medical charts of patients hospitalized for at least 48 hours. We evaluated 1497 patients. The overall patient NI rate was 3.34 per 100 patients and the infection rate per 1000 patient-days was 5.27. The most common site of infection was the respira- tory tract (36%) followed by the gastrointestinal tract (32%). S. aureus, P. aeruginosa and Salmonella species were the most frequent pathogen isolates. The lethality rate associated with NI was 10%. Describing the epidemiology of NI in this hospi- tal enable us to estimate infection occurrence, distribution and expected incidence, as well as recognizing trends and keeping track of possible outbreaks