Eur. Phys. J. C (2017) 77:555
DOI 10.1140/epjc/s10052-017-5125-x
Regular Article - Theoretical Physics
Thermal fluctuations in a hyperscaling-violation background
Behnam Pourhassan
1,a
, Mir Faizal
2,3,b
, Sudhaker Upadhyay
4,c
, Lina Al Asfar
5,d
1
School of Physics, Damghan University, Damghan 3671641167, Iran
2
Irving K. Barber School of Arts and Sciences, University of British Columbia-Okanagan, Kelowna, BC V1V 1V7, Canada
3
Department of Physics and Astronomy, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
4
Centre for Theoretical Studies, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
5
Laboratoire de Physique Corpusculaire de Clermont-Ferrand, Université Blaise Pascal, 24 Avenue des Landais, 63177 Aubière Cedex, France
Received: 1 April 2017 / Accepted: 31 July 2017 / Published online: 18 August 2017
© The Author(s) 2017. This article is an open access publication
Abstract In this paper, we study the effect of thermal fluc-
tuations on the thermodynamics of a black geometry with
hyperscaling violation. These thermal fluctuations in the ther-
modynamics of this system are produced from quantum cor-
rections of geometry describing this system. We discuss the
stability of this system using specific heat and the entire Hes-
sian matrix of the free energy. We will analyze the effects of
thermal fluctuations on the stability of this system. We also
analyze the effects of thermal fluctuations on the criticality
of the hyperscaling-violation background.
1 Introduction
It is important to associate an entropy with black holes to pre-
vent the violation of the second law of thermodynamics. This
is because if black holes were not maximum entropy objects,
then the entropy of the universe would spontaneously reduce,
whenever an object with a finite entropy crossed the horizon.
So, black holes are maximum entropy objects, and they have
more entropy than any other object with the same volume [1–
5]. The scaling of this maximum entropy with the area of the
horizon has led to the development of the holographic prin-
ciple [6,7]. The holographic principle equates the degrees of
freedom in any region of space with the degrees of freedom
on the boundary of that region.
The holographic principle is expected to be corrected near
Planck scale, as quantum gravity corrections modify the man-
ifold structure of space-time at Planck scale [8,9]. As the
a
e-mail: b.pourhassan@du.ac.ir
b
e-mail: mirfaizalmir@googlemail.com
c
e-mail: sudhakerupadhyay@gmail.com
d
e-mail: lina.alasfar@outlook.fr
holographic principle was motivated from the entropy–area
relation, it can be argued that the quantum gravity correc-
tions would also modify this entropy–area relation. Now for
a black hole with area A and entropy S
0
, original entropy–
area relation in natural units is given by S
0
= A/4. How-
ever, the corrected entropy–area relation can be written as
S = S
0
+α log A +γ
1
A
−1
+γ
2
A
−2
..., where α, γ
1
,γ
2
...,
are coefficients which depend on the details of the model. The
general structure of the corrections and their dependence on
the area is a universal feature, and it occurs in almost all
approaches to quantum gravity. The corrections to the ther-
modynamics of black holes have been studied using non-
perturbative quantum general relativity [10]. In this formal-
ism, the conformal blocks of a well defined conformal field
theory were used to study the behavior of the density of states
of a black hole. The quantum corrections to the thermody-
namics of a black hole has also been studied using the Cardy
formula [11]. The corrected thermodynamics of a black hole
has also been studied by analyzing the effect of matter fields
surrounding a black hole [12–14]. Such corrections have the
general feature that they are represented by a logarithmic
function of area.
As string theory is one of the most important approaches to
quantum gravity, it is very important to understand the effects
of quantum corrections produced by string theoretical effects.
In fact, the corrections produced by string theoretical effects
on the thermodynamics of a black hole have been studied,
and it has been observed that they produce the same general
form of the corrections as are produced by other approaches
to quantum gravity [15–18]. The corrections to the thermo-
dynamics of a dilatonic black hole have also been studied,
and they have again been observed to have the same univer-
sal form [19]. The partition function of a black hole has also
been used to analyze the corrections to the thermodynamics
of a black hole [20]. Another universal feature of almost all
theories of quantum gravity is the existence of a minimum
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