arXiv subjects

Guoyang Fu

Publications and source records attributed to Guoyang Fu.

39 records · Page 3Linked to original sources

arXiv2018

EM duality and Quasi-normal modes from higher derivatives with homogeneous disorder

We study the electromagnetic (EM) duality from $6$ derivative theory with homogeneous disorder. We find that with the change of the sign of the coupling parameter $γ_1$ of the $6$ derivative theory, the particle-vortex duality with homogeneous disorder holds more well than that without homogeneous disorder. The properties of quasinormal modes (QNMs) of this system are also explored. Similarly, for large $γ_1$, with the change of the sign of $γ_1$, the correspondence between the low frequency poles of the original theory and the ones of its dual theory, which is strongly violated in the absence of homogeneous disorder, holds well. Some new branch cuts of QNMs emerge for some system parameters.

hep-th↗

arXiv2018

Holographic fermionic spectrum with Weyl correction

We study the ferminoic spectrum with Weyl correction, which exhibits the non-Fermi liquid behavior. Also, we find that both the height of the peak of the fermionic spectrum and the dispersion relation exhibit a nonlinearity with the variety of the Weyl coupling parameter $γ$, which mean that such nonlinearity maybe ascribe to the one of the Maxwell field. Another important property of this system is that for the holographic fermionic system with $γ<0$, the degree of the deviation from Fermi liquid is heavier than that for the one with $γ>0$. It indicates that there is a transition of coupling strength in the dual boundary field theory.

hep-th↗

arXiv2017

Holographic response from higher derivatives with homogeneous disorder

In this letter, we study the charge response from higher derivatives over the background with homogeneous disorder introduced by axions. We first explore the bounds on the higher derivatives coupling from DC conductivity and the anomalies of causality and instabilities. Our results indicate no tighter constraints on the coupling than that over Schwarzschild-AdS (SS-AdS) background. And then we study the optical conductivity of our holographic system. We find that for the case with $γ_1<0$ and the disorder strength $\hatα<2/\sqrt{3}$, there is a crossover from a coherent to incoherent metallic phase as $\hatα$ increases. When $\hatα$ is beyond $\hatα=2/\sqrt{3}$ and further amplified, a peak exhibits again at low frequency. But it cannot be well fitted by the standard Drude formula and new formula for describing this behavior shall be called for. While for the holographic system with the limit of $γ_1\rightarrow 1/48$, the disorder effect drives the hard-gap-like at low frequency into the soft gap and suppresses the pronounced peak at medium frequency.

hep-th↗