27 research outputs found
Minimal Length Effects on Tunnelling from Spherically Symmetric Black Holes
In this paper, we investigate effects of the minimal length on quantum
tunnelling from spherically symmetric black holes using the Hamilton-Jacobi
method incorporating the minimal length. We first derive the deformed
Hamilton-Jacobi equations for scalars and fermions, both of which have the same
expressions. The minimal length correction to the Hawking temperature is found
to depend on the black hole's mass and the mass and angular momentum of emitted
particles. Finally, we calculate a Schwarzschild black hole's luminosity and
find the black hole evaporates to zero mass in infinite time.Comment: 18 page
Holographic DC Conductivity for a Power-law Maxwell Field
We consider a neutral and static black brane background with a probe
power-law Maxwell field. Via the membrane paradigm, an expression for the
holographic DC conductivity of the dual conserved current is obtained. We also
discuss the dependence of the DC conductivity on the temperature, charge
density and spatial components of the external field strength in the boundary
theory. Our results show that there might be more than one phase in the
boundary theory. Phase transitions could occur where the DC conductivity or its
derivatives are not continuous. Specifically, we find that one phase possesses
a charge-conjugation symmetric contribution, negative magneto-resistance and
Mott-like behavior.Comment: 19 pages, 11 figures. arXiv admin note: text overlap with
arXiv:1711.0329
Thermodynamic Instabilities of Conformal Gravity Holography in Four Dimensions
Recently, a conjecture has been proposed, which indicates a correlation
between super-entropy black holes and the thermodynamic instability
\cite{Cong:2019bud}. W.Cong et al. suggested that the (specific heat
capacity at constant volume) and (specific heat capacity at constant
pressure) of a super-entropy black hole could not be greater than zero
simultaneously as set in the extended phase space, which implies that the black
hole is unstable in extended thermodynamics. This conjecture is intriguing and
meaningful. Therefore, we did a study on that. After deriving the equations of
specific heat capacities as well as plotting the relevant curves of the
four-dimensional conformal black holes (a kind of super-entropy black hole), we
obtained regions on the graphs where and are simultaneously
greater than zero, which contradicts the conjecture that super-entropy black
hole corresponds to its thermodynamic instability. Thus far, we have provided a
counterexample to the hypothesis in \cite{Cong:2019bud}.Comment: 13 pages, 3 figure
Thermodynamic instability and the violation of reverse isoperimetric inequality in Torus-like black hole
Recently, conjectures have been made that there is a correlation between
thermodynamic instability and
super-entropy~\cite{{Johnson:2019mdp},{Cong:2019bud}}. In this paper, we
started with torus-like black holes and verified the correlation mentioned
above. After solving the specific analytical solutions of the specific heat
capacity at constant volume , the specific heat capacity at constant
pressure and plotting the figures, we obtained the results which are
consistent with the hypothesis from Ref. \cite{Cong:2019bud}. To further verify
the generality of conjectures, we explored the BTZ black hole in nonlinear
electrodynamics and phantom AdS black hole. And then the results are summarized
via a table. Ultimately, the comparison among these three black holes leads us
to the conclusion that there is no essential connection between thermodynamic
instability and super-entropy.Comment: 14 pages, 5 figures, 1 tabl