arXiv subjects

Zu-Yao Sun

Publications and source records attributed to Zu-Yao Sun.

3 recordsLinked to original sources

arXiv2015

Thermoelectric DC conductivities with momentum dissipation from higher derivative gravity

We present a mechanism of momentum relaxation in higher derivative gravity by adding linear scalar fields to the Gauss-Bonnet theory. We analytically computed all of the DC thermoelectric conductivities in this theory by adopting the method given by Donos and Gauntlett in [arXiv:1406.4742]. The results show that the DC electric conductivity is not a monotonic function of the effective impurity parameter $β$: in the small $β$ limit, the DC conductivity is dominated by the coherent phase, while for larger $β$, pair creation contribution to the conductivity becomes dominant, signaling an incoherent phase. In addition, the DC heat conductivity is found independent of the Gauss-Bonnet coupling constant.

hep-th↗

arXiv2010

Dynamics of phantom model with O(N) symmetry in loop quantum cosmology

Many astrophysical data show that the expansion of our universe is accelerating. In this paper, we study the model of phantom with O(N) symmetry in background of loop quantum cosmology(LQC). We investigate the phase-space stability of the corresponding autonomous system and find no stable node but only 2 saddle points in the field of real numbers. The dynamics is similar to the single-field phantom model in LQC[1]. The effect of O(N) symmetry just influence the detail of the universe's evolution. This is a sharp contrast with the result in general relativity, in which the dynamics of scalar fields models with O$(N)$ symmetry are quite different from the single-field models[2][3][4].

gr-qc↗

arXiv2004

Phantom Cosmology with Non-minimally Coupled Real Scalar Field

We find that the expansion of the universe is accelerating by analyzing the recent observation data of type $\textsc{I}a$ supernova(SN-Ia) .It indicates that the equation of state of the dark energy might be smaller than -1,which leads to the introduction of phantom models featured by its negative kinetic energy to account for the regime of equation of state parameter $w<-1$.In this paper the possibility of using a non-minimally coupled real scalar field as phantom to realize the equation of state parameter $w<-1$ is discussed.The main equations which govern the evolution of the universe are obtained.Then we rewrite them with the observable quantities.

gr-qc↗