119281721
Holographic p-wave Josephson junction
In this work we generalized holographic model for s-wave DC Josephson junction constructed in arXiv:1101.3326[hep-th] to a holographic description for p-wave Josephson junction. By solving numerically the coupled equations of motion of Yang-Mills theory for a non-Abelian SU(2) gauge fields in (3+1)-dimensional AdS spacetimes, we shown that DC current of the p-wave Josephson junction is proportional to the sine of the phase difference across the junction like the s-wave case.
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.
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.
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.
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.
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.
14525091
Inflationary non-Gaussianity from thermal fluctuations
We calculate the contribution of fluctuations with a thermal origin to the inflationary non-Gaussianity. We find that even a small component of radiation can lead to a large non-Gaussianity. We show that this thermal non-Gaussianity always has positive f(NL). We illustrate our result in the chain inflation model and the very weakly dissipative warm inflation model. We show that f(NL) similar to O(1) is general in such models. If we allow a modified equation of state, or some decoupling effects, a large thermal non-Gaussianity of order f(NL) > 5 or even f(NL) similar to 100 can be produced. We also show that the power spectrum of chain inflation should have a thermal origin. In the appendix, we give a clarification on the different conventions used in the literature related to the calculation of f(NL).
119276160
New determination of the 13C(a, n)16O reaction rate and its influence on the s-process nucleosynthesis in AGB stars
We present a new measurement of the $\alpha$-spectroscopic factor ($S_\alpha$) and the asymptotic normalization coefficient (ANC) for the 6.356 MeV 1/2$^+$ subthreshold state of $^{17}$O through the $^{13}$C($^{11}$B, $^{7}$Li)$^{17}$O transfer reaction and we determine the $\alpha$-width of this state. This is believed to have a strong effect on the rate of the $^{13}$C($\alpha$, $n$)$^{16}$O reaction, the main neutron source for {\it slow} neutron captures (the $s$-process) in asymptotic giant branch (AGB) stars. Based on the new width we derive the astrophysical S-factor and the stellar rate of the $^{13}$C($\alpha$, $n$)$^{16}$O reaction. At a temperature of 100 MK our rate is roughly two times larger than that by \citet{cau88} and two times smaller than that recommended by the NACRE compilation. We use the new rate and different rates available in the literature as input in simulations of AGB stars to study their influence on the abundances of selected $s$-process elements and isotopic ratios. There are no changes in the final results using the different rates for the $^{13}$C($\alpha$, $n$)$^{16}$O reaction when the $^{13}$C burns completely in radiative conditions. When the $^{13}$C burns in convective conditions, as in stars of initial mass lower than $\sim$2 $M_\sun$ and in post-AGB stars, some changes are to be expected, e.g., of up to 25% for Pb in our models. These variations will have to be carefully analyzed when more accurate stellar mixing models and more precise observational constraints are available.
118542607
Cosmological constraints on the generalized holographic dark energy
We use the Markov Chain Monte Carlo method to investigate global constraints on the generalized holographic (GH) dark energy with flat and non-flat universe from the current observed data: the Union2 dataset of type supernovae Ia (SNIa), high-redshift Gamma-Ray Bursts (GRBs), the observational Hubble data (OHD), the cluster X-ray gas mass fraction, the baryon acoustic oscillation (BAO), and the cosmic microwave background (CMB) data. The most stringent constraints on the GH model parameter are obtained. In addition, it is found that the equation of state for this generalized holographic dark energy can cross over the phantom boundary wde=−1.
125751010
Energy and centrality dependence of the contribution from leading particles to charged-particle pseudorapidity distribution
44351609
A no-go theorem for generalized vector Galileons on flat spacetime
A bstractWe explore the possibility for generalized electromagnetism on flat spacetime. For a single copy of U(1) gauge theory, we show that the Galileon-type generalization of electromagnetism is forbidden. Given that the equations of motion for the vector field are gauge invariant and Lorentz invariant, follow from an action and contain no more than second derivative on Aμ, the equations of motion are at most linear with respect to second derivative of Aμ.