We study glueballs in the holographic gauge theories living in a curved space-time. The dual bulk is obtained as a solution of the type IIB superstring theory with two parameters, which correspond to the four-dimensional cosmological constant λ and the dark radiation C, respectively. The theory is in the confining phase for λ<0 and small C, then we observe stable glueball states in this theory. However, the stability of the glueball states is lost when the density of the dark radiation (C) increases and exceeds a critical point. Above this point, the dark radiation works as the heat bath of the Yang-Mills theory since the event horizon appears. Thus the system is thermalized, and the theory is in a finite temperature deconfinement phase, namely in the QGP phase. We observe this transition process through the glueball spectra which varies dramatically with C. We also examined the entanglement entropy of the system to find a clue of this phase transition and the role of the dark radiation C in the entanglement entropy.
|Journal||Physical Review D - Particles, Fields, Gravitation and Cosmology|
|Publication status||Published - 2014 Dec 24|
ASJC Scopus subject areas
- Nuclear and High Energy Physics
- Physics and Astronomy (miscellaneous)