Browsing by Author "Yuan, Pei-Hung"

Now showing 1 - 7 of 7

A refined holographic QCD model and QCD phase structure
(2014-11-26)
Yang, Yi
;
Yuan, Pei-Hung
;
電子物理學系
;
物理研究所
;
Department of Electrophysics
We consider the Einstein-Maxwell-dilaton system with an arbitrary kinetic gauge function and a dilaton potential. A family of analytic solutions is obtained by the potential reconstruction method. We then study its holographic dual QCD model. After fixing the kinetic gauge function by requesting the linear Regge spectrum of mesons, we calculate the free energy to obtain the phase diagram of the holographic QCD model.
Approaching confinement structure for light quarks in a holographic soft wall QCD model
(2017-09-12)
Li, Meng-Wei
;
Yang, Yi
;
Yuan, Pei-Hung
;
電子物理學系
;
物理研究所
We study the confinement-deconfinement phase transition in a holographic soft-wall QCD model. By solving the Einstein-Maxwell-scalar system analytically, we obtain the phase structure of the black hole backgrounds. We then impose probe open strings in such a background to investigate the confinement-deconfinement phase transition from different open string configurations under various temperatures and chemical potentials. Furthermore, we study the Wilson loop by calculating the minimal surface of the probing open string world sheet and obtain the Cornell potential in the confinement phase analytically.
Confinement-deconfinement phase transition for heavy quarks in a soft wall holographic QCD model
(2015-12-28)
Yang, Yi
;
Yuan, Pei-Hung
;
電子物理學系
;
物理研究所
;
Department of Electrophysics
We study confinement-deconfinement phase transition for heavy quarks in a soft wall holographic QCD model. We consider a black hole background in an Einstein-Maxwell- scalar system and add probe open strings to the background. Combining the various configurations of the open strings and the phase structure of the black hole background itself, we obtain the confinement-deconfinement phase diagram for heavy quarks in the holographic QCD model.
Inverse magnetic catalysis in the soft-wall model of AdS/QCD
(2017-02-07)
Li, Danning
;
Huang, Mei
;
Yang, Yi
;
Yuan, Pei-Hung
;
電子物理學系
Magnetic effects on chiral phase transition have been investigated in a modified soft-wall AdS/QCD model, in which the dilaton field is taken to be negative at the ultraviolet region and positive at the infrared region as in Phys. Rev. D 93 (2016) 101901 and JHEP 04 (2016) 036. The magnetic field is introduced into the background geometry by solving the Einstein-Maxwell system. After embedding the magnetized background geometry into the modified soft-wall model, the magnetic field dependent behavior of chiral condensate is worked out numerically. It is found that, in the chiral limit, the chiral phase transition remains as a second order at finite magnetic field B, while the symmetry restoration temperature and chiral condensate decrease with the increasing of magnetic field in small B region. When including finite quark mass effect, the phase transition turns to be a crossover one, and the transition temperature still decreases with increasing magnetic field B when B is not very large. In this sense, inverse magnetic catalysis effect is observed in this modified soft-wall AdS/QCD model.
Phase structure in a dynamical soft-wall holographic QCD model
(2013-04-01)
He, Song
;
Wu, Shang-Yu
;
Yang, Yi
;
Yuan, Pei-Hung
;
物理研究所
We consider the Einstein-Maxwell-dilaton system with an arbitrary kinetic gauge function and a dilaton potential. A family of analytic solutions is obtained by the potential reconstruction method. We then study its holographic dual QCD model. The kinetic gauge function can be fixed by requesting the linear Regge spectrum of mesons. We calculate the free energy to obtain the phase diagram of the holographic QCD model and interpret our result as the heavy quarks system by comparing the recent lattice QCD simulation. We finally obtain the equations of state in our model.
Rotating black holes and Coriolis effect
(2016-10-10)
Chou, Chia-Jui
;
Wu, Xiaoning
;
Yang, Yi
;
Yuan, Pei-Hung
;
電子物理學系
In this work, we consider the fluid/gravity correspondence for general rotating black holes. By using the suitable boundary condition in near horizon limit, we study the correspondence between gravitational perturbation and fluid equation. We find that the dual fluid equation for rotating black holes contains a Coriolis force term, which is closely related to the angular velocity of the black hole horizon. This can be seen as a dual effect for the frame-dragging effect of rotating black hole under the holographic picture. (C) 2016 The Authors. Published by Elsevier B.V.
Universal behaviors of speed of sound from holography
(2018-06-13)
Yang, Yi
;
Yuan, Pei-Hung
;
電子物理學系
;
物理研究所
;
Department of Electrophysics
We investigate the speed of sound in (d + 1)-dimensional quantum field theory by studying its dual (d thorn 2)-dimensional gravity theory from gauge/gravity correspondence. Instead of the well-known conformal limit c(s)(2) -> 1/d at high temperature, we reveal two more universal quantities in various limits: c(s)(2) -> (d - 1)/16 pi at low temperature and c(s)(2) -> (d - 1)/16 pi d at large chemical potential.