Physics Letters B 781 (2018) 553–560
Contents lists available at ScienceDirect
Physics Letters B
www.elsevier.com/locate/physletb
Thermal fluctuations of dilaton black holes in gravity’s rainbow
M. Dehghani
Department of Physics, Razi University, Kermanshah, Iran
a r t i c l e i n f o a b s t r a c t
Article history:
Received
31 March 2018
Received
in revised form 19 April 2018
Accepted
19 April 2018
Available
online 24 April 2018
Editor:
N. Lambert
Keywords:
Four-dimensional
black hole
Black
hole with scalar hair
Rainbow
gravity
Thermal
fluctuations
In this work, thermodynamics and phase transition of some new dilaton black hole solutions have been
explored in the presence of the rainbow functions. By introducing an energy dependent space time,
the dilaton potential has been obtained as the linear combination of two Liouville-type potentials and
three new classes of black hole solutions have been constructed. The conserved and thermodynamic
quantities of the new dilaton black holes have been calculated in the energy dependent space times.
It has been shown that, even if some of the thermodynamic quantities are affected by the rainbow
functions, the thermodynamical first law still remains valid. Also, the impacts of rainbow functions on the
stability or phase transition of the new black hole solutions have been investigated. Finally, the quantum
gravitational effects on the thermodynamics and phase transition of the solutions have been studied
through consideration of the thermal fluctuations.
© 2018 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license
(http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP
3
.
1. Introduction
Promoting of the usual energy-momentum dispersion relation
to the modified dispersion relation is one of the findings of loop
quantum gravity and the quantum models based on the non-
commutative
geometry [1–6]. This modification which is realized
at the Planck-scale regime leads to the violation of the Lorentz
symmetry as one of the most important symmetries in the uni-
verse.
The deformed or doubly special relativity, as a modified for-
malism
of special relativity, has been proposed to preserve Lorentz
symmetry in the modified dispersion relation [6–8]. In the high
energy formalism of the special relativity, known as the doubly
special relativity, in addition to the speed of light the Planck en-
ergy
is considered as a universal constant. In this theory, it is
impossible for a particle to attain an energy and a velocity greater
than the Planck energy and light velocity, respectively. It is ac-
complished
by utilizing a nonlinear Lorentz transformation in the
momentum space in a way that the energy-momentum relation
appears with the corrections in the order of the Planck length. Also
the Planck-scale corrected dispersion relation preserves a deformed
Lorentz symmetry [9–11]. It seems that the violation of Lorentz
symmetry plays an essential rule in constructing the quantum the-
ory
of gravity. It is notable that, due to the existence of an unstable
perturbative string vacuum, violation of the Lorentz symmetry can
also occur in the string theory [12].
E-mail address: m .dehghani @razi .ac .ir.
Recently, Magueijo and Smolin have extended the doubly spe-
cial
relativity to the curved space times. This doubly general theory
of relativity is called rainbow gravity (or gravity’s rainbow) [13].
The name rainbow gravity comes from the fact that in this theory
the space time geometry depends on the energy of a test parti-
cle
E. Therefore, instead of a single metric, there is a family of
metrics (rainbow metrics) which are parameterized by the ratio
ε = E/E
p
, where E
P
denotes the Planck energy [14]. Therefore,
gravity’s rainbow, just like the Horava–Lifshitz gravity theory, can
be considered as the ultraviolet completion of the Einstein’s gen-
eral
relativity. There is a close relation between the rainbow and
Horava–Lifshitz gravity theories. Both of them are based on pro-
moting
of the usual dispersion relation to the modified dispersion
relation [15–17]. As pointed out by many authors, a general modi-
fied
dispersion relation may be written as [18–23]
E
2
f
2
(ε) − p
2
g
2
(ε) =m
2
, (1.1)
where, the functions f (ε) and g(ε) are known as the rainbow
functions, which are required to satisfy the following conditions
lim
ε→0
f (ε) = 1, and lim
ε→0
g(ε) =1. (1.2)
By these requirements the standard dispersion relation can be re-
covered
in the infrared limit of the theory. It must be noted that
different functional forms of the rainbow functions are proposed
which are based on different phenomenological motivations. Some
of the proposed models for the temporal and spatial rainbow func-
tions
can be found in Refs. [24–28].
https://doi.org/10.1016/j.physletb.2018.04.039
0370-2693/
© 2018 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by
SCOAP
3
.