119228450
Holographic superconductor on Q-lattice
A bstractWe construct the simplest gravitational dual model of a superconductor on Q-lattices. We analyze the condition for the existence of a critical temperature at which the charged scalar field will condense. In contrast to the holographic superconductor on ionic lattices, the presence of Q-lattices will suppress the condensate of the scalar field and lower the critical temperature. In particular, when the Q-lattice background is dual to a deep insulating phase, the condensation would never occur for some small charges. Furthermore, we numerically compute the optical conductivity in the superconducting regime. It turns out that the presence of Q-lattice does not remove the pole in the imaginary part of the conductivity, ensuring the appearance of a delta function in the real part. We also evaluate the gap which in general depends on the charge of the scalar field as well as the Q-lattice parameters. Nevertheless, when the charge of the scalar field is relatively large and approaches the probe limit, the gap becomes universal with ωg ≃ 9Tc which is consistent with the result for conventional holographic superconductors.
118494690
The St\"uckelberg Holographic Superconductors in Constant External Magnetic Field
We investigate the St\"{u}ckelberg holographic superconductor in present of the constant external magnetic field. We observe that a critical value of magnetic field exists as the cases in usual holographic superconductor. Furthermore, we find that the applied magnetic field strongly influence the phase transition of this model and have a jump in the condensate at the critical temperature even for $c_{4}=1$.
118730033
Anomaly freedom of the vector modes with holonomy corrections in perturbative Euclidean loop quantum gravity
We study the perturbation of the effective Hamiltonian constraint with holonomy correction from Euclidean loop quantum gravity. The Poisson bracket between the corrected Hamiltonian constraint and the diffeomorphism constraint is derived for vector modes. Some specific form of the holonomy correction function $f^{i}_{cd}$ is found, which satisfies that the constraint algebra is anomaly-free. This result confirms the possibility of non-trivial holonomy corrections from full theory while preserving anomaly-free constraint algebra in the perturbation framework. It also gives valuable hints on the possible form of holonomy corrections in effective loop quantum gravity.
119201080
Holographic fermions in charged Gauss-Bonnet black hole
We study the properties of the Green’s functions of the fermions in charged Gauss-Bonnet black hole. What we want to do is to investigate how the presence of Gauss-Bonnet coupling constant α affects the dispersion relation, which is a characteristic of Fermi or non-Fermi liquid, as well as what properties such a system has, for instance, the Particle-hole (a)symmetry. One important result of this research is that we find for q = 1, the behavior of this system is different from that of the Landau Fermi liquid and so the system can be candidates for holographic dual of generalized non-Fermi liquids. More importantly, the behavior of this system increasingly similar to that of the Landau Fermi liquid when α is approaching its lower bound. Also we find that this system possesses the Particle-hole asymmetry when q ≠ 0, another important characteristic of this system. In addition, we also investigate briefly the cases of the charge dependence.
119286437
Dynamic gap from holographic fermions in charged dilaton black branes
A bstractWe report a dynamical formation of a (Mott) gap from holographic fermions. By coupling a fermion field with dipole action to the charged dilaton black branes with a Lifshitz like IR geometry and AdS4 boundary, we find that when the dipole interaction is large enough, spectral weight is transferred between bands, and beyond a critical dipole interaction, a gap emerges in the fermion density of states. The value of the gap becomes larger as the strength of the interaction keeps increasing.
118750591
Chaos from the ring string in a Gauss-Bonnet black hole in AdS5 space
By the Poincare sections, the dynamical behaviors of the ring string in the AdS-Gauss-Bonnet (AdS-GB) black hole are studied. A threshold value of the Gauss-Bonnet (GB) parameter $\lambda$ are found by the numerical method, below which the behavior of this dynamical system is no-chaotic and above which the behavior becomes gradually chaotic. The chaotic behavior becomes stronger with the increases of GB parameter. It is different from the case in the AdS-Schwarzschild black hole, which is weakly chaotic. Furthermore, we confirm our findings by the Fast Lyapunov indicators.
118488848
Photoproduction of bound states with hidden charm
The photo-production of $J/\Psi$-$^3He$ bound state ($[^3He]_{J/\Psi}$) on a $^4He$ target has been investigated using the impulse approximation. The calculations have been performed using several $\gamma+N \rightarrow J/\Psi +N$ models based on the Pomeron-exchange and accounting for the pion-exchange mechanism at low energies. The $J/\Psi$ wavefunctions in $[^3He]_{J/\Psi}$ are generated from various $J/\Psi$-nucleus potentials which are constructed by either using a procedure based on the Pomeron-quark coupling mechanism or folding a $J/\Psi$-N potential ($v_{J/\Psi,N}$) into the nuclear densities. We consider $v_{J/\Psi,N}$ derived from the effective field theory approach, Lattice QCD, and Pomeron-quark coupling mechanism. The upper bound of the predicted total cross sections is about $0.1 - 0.3$ pico-barn. We also consider the possibility of photo-production of a six quark-$J/\Psi$ bound state ($[q^6]_{J/\Psi})$ on the $^3He$ target. The Compound Bag Model of $NN$ scattering and the quark cluster model of nuclei are used to estimate the $[q^6]$-N wavefunction in $^3He$ by imposing the condition that the calculated $^3He$ charge form factor must be consistent with what is predicted by the conventional nuclear model. The upper bound of the predicted total cross sections of $\gamma + ^3He \rightarrow [q^6]_{J/\Psi} +N$ is about 2 - 4 pico-barn, depending on the model of $\gamma+N \rightarrow J/\Psi +N$ used in the calculations. Our results call for the need of precise measurements of $\gamma+p \rightarrow J/\Psi +p$ and also the $\gamma+^2H\rightarrow J/\Psi +n + p $ reactions near the threshold.
119240361
High-frequency behavior of w-mode pulsations of compact stars
We study the asymptotic behavior of the quasinormal modes (QNMs) of $w$-mode pulsations of compact stars in the high-frequency regime. We observe that both the axial and polar $w$-mode QNMs attain similar asymptotic behaviors in spite of the fact that they are described by two totally different differential equation systems. We obtain robust asymptotic formulas relating $w$-mode QNMs of different polarities and different angular momenta. To explore the physical reason underlying such similarity, we first derive a high-frequency approximation for the polar $w$-mode oscillations to unify the descriptions for both cases. Then, we develop WKB-type analyses for them and quantitatively explain the observed asymptotic behaviors for polytropic stars and quark stars. We also point out that such asymptotic behaviors for realistic stars are strongly dependent on the equation of state near the stellar surface.
41259393
Electrostatic and magnetostatic solutions in a Lorentz-violating electrodynamics model
We propose an effective Lorentz-violating electrodynamics model via the static de Sitter metric, which is deviated from the Minkowski metric by a minuscule amount depending on the cosmological constant. We obtain the electromagnetic field equations via the vierbein decomposition of the tensors. In addition, as an application of the electromagnetic field equations obtained, we derive the solutions of the electrostatic field and the magnetostatic field due to a point charge and a circle current, respectively, and discuss the implication of the effect of Lorentz violation in our electromagnetic theory.
119034794
Note on refined topological vertex, Jack polynomials and instanton counting
In this article, we calculated the refined topological vertex for the one parameter case using the Jack symmetric functions. Also, we obtain the partition function for elliptic N=2 models, the results coincide with those of Nekrasov instanton counting partition functions for the $N=2^{\ast}$ theories.
106116857
Study of K- p ---> Lambda pi+ pi-, Lambda pi0 and gamma N ---> K+ Sigma*