119207378
Effects of temperature on thick branes and the fermion (quasi-)localization
Following Campos’s work [Phys. Rev. Lett. 88 (2002) 141602], we investigate the effects of temperature on flat, de Sitter (dS), and anti-de Sitter (AdS) thick branes in five-dimensional (5D) warped spacetime, and on the fermion (quasi-)localization. First, in the case of flat brane, when the critical temperature reaches, the solution of the background scalar field and the warp factor is not unique. So the thickness of the flat thick brane is uncertain at the critical value of the temperature parameter, which is found to be lower than the one in flat 5D spacetime. The mass spectra of the fermion Kaluza-Klein (KK) modes are continuous, and there is a series of fermion resonances. The number and lifetime of the resonances are finite and increase with the temperature parameter, but the mass of the resonances decreases with the temperature parameter. Second, in the case of dS brane, we do not find such a critical value of the temperature parameter. The mass spectra of the fermion KK modes are also continuous, and there is a series of fermion resonances. The effects of temperature on resonance number, lifetime, and mass are the same with the case of flat brane. Last, in the case of AdS brane, the critical value of the temperature parameter can less or greater than the one in the flat 5D spacetime. The spectra of fermion KK modes are discrete, and the mass of fermion KK modes does not decrease monotonically with increasing temperature parameter.
39616698
Fermionic zero modes in gauge and gravity backgrounds on T-2
Here we study fermionic zero modes in gauge and gravity backgrounds taking a two-dimensional compact manifold T-2 as extra dimensions. The result is that there exist massless Dirac fermions which have normalizable zero modes under quite general assumptions about these backgrounds on the bulk. Several special cases of gauge background on the torus are discussed and some simple fermionic zero modes axe obtained.
53470154
Competition between s-wave order and d-wave order in holographic superconductors
A bstractWe study competition between s-wave order and d-wave order through two holographic superconductor models. We find that once the coexisting phase appears, it is always thermodynamically favored, and that the coexistence phase is narrow and one condensate tends to kill the other. The phase diagram is constructed for each model in terms of temperature and the ratio of charges of two orders. We further compare the behaviors of some thermodynamic quantities, and discuss the different aspects and identical ones between two models.
14109465
Fermions coupled with self-dual vortex background on a torus
Abstract: We study fermionic zero modes in the self-dual vortex background on an extra torus in 5+1 dimensions. It is shown that the self-dual vortex arises from the symmetric phase and the asymmetric phase of Higgs field in the context of generalized Abelian Higgs model. Then we analyze the Dirac operator on the extra two-dimensional space and the effective Lagrangian of four-dimensional fermion with the vortex background. Solving the Dirac equation, we obtain the fermionic zero modes in two simple cases. It is shown that the vortex background contributes a phase shift to the fermionic zero modes, and this phase is determined by the topology of the extra dimensions, it can be observed through Aharonov-Bohm effect. For the anti-vortex case, the corresponding zero modes present a singular behavior at the zero point of Higgs field. While for the vacuum one, they are non-singular.
32300667
Non-relativistic Josephson junction from holography
A bstractWe construct a Josephson junction in non-relativistic case with a Lifshitz geometry as the dual gravity. We investigate the effect of the Lifshitz scaling in comparison with its relativistic counterpart. The standard sinusoidal relation between the current and the phase difference is found for various Lifshitz scalings characterised by the dynamical critical exponent. We also find the exponential decreasing relation between the condensate of the scalar operator within the barrier at zero current and the width of the weak link, as well as the relation between the critical current and the width. Nevertheless, the coherence lengths obtained from two exponential decreasing relations generically have discrepancies for non-relativistic dual.
118404205
Thermodynamic geometry of black hole in the deformed Hořava-Lifshitz gravity
We investigate the thermodynamic geometry and phase transition of Kehagias-Sfetsos black hole in the deformed Hořava-Lifshitz gravity with coupling constant λ = 1. The phase transition in black-hole thermodynamics is thought to be associated with the divergence of the capacities. And the structures of these divergent points are studied. We also find that the thermodynamic curvature produced by the Ruppeiner metric is positive definite for all r+ > r− and is divergent at η2 = 0 corresponding to the divergent points of CΦ and CT . These results suggest that the microstructure of the black hole has an effective repulsive interaction, which is very similar to the ideal gas of fermions. These may shed some light on the microstructure of the black hole.
67826810
Deprojected analysis of Abell 1835 observed with Chandra and compared with XMM-Newton
Using a deprojection technique, we study the X-ray properties of the galaxy cluster Abell 1835 observed with Chandra, including temperature, abundance, electron density, gas mass fraction, and total mass. A comparison with the results without deprojection shows that the properties do not change much. When we compare the results with those of XMM-Newton, the difference between the temperature profiles derived from Chandra and XMM-Newton data still exists, even if the point-spread function effect of XMM-Newton is corrected. To investigate the reasons for the difference, we used the spectra to cross-calibrate the temperatures. They show that the Chandra spectra can be fitted well with XMM-Newton temperatures. Furthermore, we derive the electron density profile from Chandra data with XMM-Newton temperatures and calculate the projected mass, which is consistent with the XMM-Newton mass and a little lower than the weak lensing mass at r(500). Thus, it seems that the temperature derived from XMM-Newton may be more reliable.
119206095
The First Infrared Telescope in Tibet Plateau, China
We plan to install an infrared telescope at the new site of Tibet, China. The primary mirror diameter is 50cm, and the focal ratio F8. The Xenics 640\times512 near infrared camera is employed, equipped with a dedicated high speed InGaAs detector array, working up to 1.7{\mu}m. The new site is located on 5100m mountain, near Gar town, Ali, where is an excellent site for both infrared and submillimeter observations. The telescope will be remotely controlled through internet. The goal of IRT is to make site testing, detect variable stars, and search for extrasolar planets.
24223006
A proposed multipole wiggler for CAMD
New insertion devices, such as a multi-pole wiggler (MPW), are being considered for CAMD. This is a consequence of the growth of CAMD's research program over the last several years, in particular after the commissioning of a 7 T wiggler, which has produced a demand for both higher beam brightness and flux density. A proposal has been submitted to the National Science Foundation for funding for a MPW which would replace the existing 7 T wavelength shifter. The outline specification for this new device is presented and also results of tests of modified optics for the CAMD storage ring which will be needed to accommodate the MPW. The modified optics have a reduced vertical aperture requirement of 20 mm at the location of the MPW. It will also be necessary to up rate the RF system to cope with the increased radiation loss.
120571188
Large Synoptic Survey Telescope: Dark Energy Science Collaboration
This white paper describes the LSST Dark Energy Science Collaboration (DESC), whose goal is the study of dark energy and related topics in fundamental physics with data from the Large Synoptic Survey Telescope (LSST). It provides an overview of dark energy science and describes the current and anticipated state of the field. It makes the case for the DESC by laying out a robust analytical framework for dark energy science that has been defined by its members and the comprehensive three-year work plan they have developed for implementing that framework. The analysis working groups cover five key probes of dark energy: weak lensing, large scale structure, galaxy clusters, Type Ia supernovae, and strong lensing. The computing working groups span cosmological simulations, galaxy catalogs, photon simulations and a systematic software and computational framework for LSST dark energy data analysis. The technical working groups make the connection between dark energy science and the LSST system. The working groups have close linkages, especially through the use of the photon simulations to study the impact of instrument design and survey strategy on analysis methodology and cosmological parameter estimation. The white paper describes several high priority tasks identified by each of the 16 working groups. Over the next three years these tasks will help prepare for LSST analysis, make synergistic connections with ongoing cosmological surveys and provide the dark energy community with state of the art analysis tools. Members of the community are invited to join the LSST DESC, according to the membership policies described in the white paper. Applications to sign up for associate membership may be made by submitting the Web form at http://www.slac.stanford.edu/exp/lsst/desc/signup.html with a short statement of the work they wish to pursue that is relevant to the LSST DESC.
5692175
Effects of correlation between merging steps on the global halo formation
The excursion set theory of halo formation is modified by adopting the fractional Brownian motion, to account for possible correlation between merging steps. We worked out analytically the conditional mass function, halo merging rate and formation time distribution in the spherical collapse model. We also developed an approximation for the ellipsoidal collapse model and applied it to the calculation of the conditional mass function and the halo formation time distribution. For models in which the steps are positively correlated, the halo merger rate is enhanced when the accreted mass is less than similar to 25M*, while for the negatively correlated case this rate is reduced. Compared with the standard model in which the steps are uncorrelated, the models with positively correlated steps produce more aged population in small mass haloes and more younger population in large mass haloes, while for the models with negatively correlated steps the opposite is true. An examination of simulation results shows that a weakly positive correlation between successive merging steps appears to fit best. We have also found a systematic effect in the measured mass function due to the finite volume of simulations. In future work, this will be included in the halo model to accurately predict the three-point correlation function estimated from simulations.