arXiv subjects

Yun Soo Myung

Publications and source records attributed to Yun Soo Myung.

At least 163 records · Page 9Linked to original sources

arXiv2010

Dilaton gravity approach to three dimensional Lifshitz black hole

The z=3 Lifshitz black hole is an exact black hole solution to the new massive gravity in three dimensions. In order to understand this black hole clearly, we perform a dimensional reduction to two dimensional dilaton gravity by utilizing the circular symmetry. Considering the linear dilaton, we find the same Lifshitz black hole in two dimensions. This implies that all thermodynamic quantities of the z=3 Lifshitz black hole could be obtained from its corresponding black hole in two dimensions. As a result, we derive the temperature, mass, heat capacity, Bekesnstein-Hawking entropy, and free energy.

hep-th↗

arXiv2010

Slowly rotating black holes in the Horava-Lifshitz gravity

We investigate slowly rotating black holes in the Hořava-Lifshitz (HL) gravity. For $Λ_W=0$ and $λ=1$, we find a slowly rotating black hole of the Kehagias-Sfetsos solution in asymptotically flat spacetimes. We discuss their thermodynamic properties by computing mass, temperature, angular momentum, and angular velocity on the horizon.

hep-th↗

arXiv2010

Chaotic universe in the z=2 Hovava-Lifshitz gravity

The deformed z=2 Horava-Lifshitz gravity with coupling constant w leads to a nonrelativistic "mixmaster" cosmological model. The potential of theory is given by the sum of IR and UV potentials in the ADM Hamiltonian formalism. It turns out that adding the UV-potential cannot suppress chaotic behaviors existing in the IR-potential.

gr-qc↗

arXiv2010

Entropic force versus temperature force

We introduce the cavity enclosing a source mass $M$ to define the temperature force. Starting with the Tolman temperature in the stationary spacetime, we find a non-relativistic temperature $T_{non}= T_\infty(1-Φ/c^2)$ with the Newtonian potential $Φ$. This temperature could be also derived from the Tolman-Ehrenfest effect, satisfying a relation of $T=T_{\infty}e^{-Φ/c^2}$ with the local temperature $T$. Finally, we derive the temperature force $\vec{F}_{tem}=mc^2(\vec{\nabla} \ln T )$ which leads to the Newtonian force law without introducing the holographic screen defined by holographic principle and equipartition law for entropic force.

hep-th↗

arXiv2010

Lifshitz black holes in the Hořava-Lifshitz gravity

We investigate the Lifshitz black holes from the Hořava-Lifshitz gravity by comparing with the Lifshitz black hole from the 3D new massive gravity. We note that these solutions all have single horizons. These black holes are very similar to each other when studying their thermodynamics. It is shown that a second order phase transition is unlikely possible to occur between $z=3,2$ Lifshitz black holes and $z=1$ Hořava black hole.

hep-th↗

arXiv2010

Massive graviton propagation of the deformed Hořava-Lifshitz gravity without projectability condition

We study graviton propagations of scalar, vector, and tensor modes in the deformed Hořava-Lifshitz gravity ($λR$-model) without projectability condition. The quadratic Lagrangian is invariant under diffeomorphism only for $λ=1$ case, which contradicts to the fact that $λ$ is irrelevant to a consistent Hamiltonian approach to the $λR$ model. In this case, as far as scalar propagations are concerned, there is no essential difference between deformed Hořava-Lifshitz gravity ($λR$-model) and general relativity. This implies that there are two degrees of freedom for a massless graviton without Hořava scalar, and five degrees of freedom appear for a massive graviton when introducing Lorentz-violating and Fierz-Pauli mass terms. Finally, it is shown that for $λ=1$, the vDVZ discontinuity is absent in the massless limit of Lorentz-violating mass terms by considering external source terms.

hep-th↗

arXiv2010

Extremal black holes in the Hořava-Lifshitz gravity

We study the near-horizon geometry of extremal black holes in the $z=3$ Hořava-Lifshitz gravity with a flow parameter $λ$. For $λ>1/2$, near-horizon geometry of extremal black holes are AdS$_2 \times S^2$ with different radii, depending on the (modified) Hořava-Lifshitz gravity. For $1/3\le λ\le 1/2$, the radius $v_2$ of $S^2$ is negative, which means that the near-horizon geometry is ill-defined and the corresponding Bekenstein-Hawking entropy is zero. We show explicitly that the entropy function approach does not work for obtaining the Bekenstein-Hawking entropy of extremal black holes.

hep-th↗

arXiv2010

Entropic force and entanglement system

We introduce the isothermal cavity, static holographic screen, and accelerating surface as holographic screen to study the entropic force in the presence of the Schwarzschild black hole. These may merge to provide a consistent holographic screen to define the entropic force on the stretched horizon near the event horizon. Considering the similarity between the stretched horizon of black hole and the entanglement system, we may define the entropic force in the entanglement system without referring the source mass.

hep-th↗

arXiv2010

Nonpropagation of massive mode on AdS2 in topologically massive gravity

Making use of Achucarro-Ortiz (AO) type of dimensional reduction, we study the topologically massive gravity with a negative cosmological constant on AdS2 spacetimes. For a constant dilaton, this two-dimensional model also admits three AdS2 vacuum solutions, which are related to two AdS3 and warped AdS3 backgrounds with an identification upon uplifting three dimensions. We carry out the perturbation analysis around these backgrounds to find what is a physically propagating field. However, it turns out that there is no propagating massive mode on AdS2 background, in contrast to the Kaluza-Klein (KK) type of dimensional reduction. We note that two dimensionally reduced actions are different and thus, the non-equivalence of their on-shell amplitudes is obtained.

hep-th↗

arXiv2010

Thermodynamics of Hořava-Lifshitz black holes

We study black holes in the Hořava-Lifshitz gravity with a parameter $λ$. For $1/3 \le λ< 3$, the black holes behave the Lifshitz black holes with dynamical exponent $0 < z \le 4$, while for $λ> 3$, the black holes behave the Reissner-Nordström type black hole in asymptotically flat spacetimes. Hence, these all are quite different from the Schwarzschild-AdS black hole of Einstein gravity. The temperature, mass, entropy, and heat capacity are derived for investigating thermodynamic properties of these black holes.

hep-th↗

arXiv2010

Area spectrum of slowly rotating black holes

We investigate the area spectrum for rotating black holes which are Kerr and BTZ black holes. For slowly rotating black holes, we use the Maggiore's idea combined with Kunstatter's method to derive their area spectra, which are equally spaced.

hep-th↗

arXiv2010

Entropy function approach to charged BTZ black hole

We find solution to the metric function f(r)=0 of charged BTZ black hole making use of the Lambert function. The condition of extremal charged BTZ black hole is determined by a non-linear relation of M_e(Q)=Q^2(1-\ln Q^2). Then, we study the entropy of extremal charged BTZ black hole using the entropy function approach. It is shown that this formalism works with a proper normalization of charge Q for charged BTZ black hole because AdS_2 x S^1 represents near-horizon geometry of the extremal charged BTZ black hole. Finally, we introduce the Wald's Noether formalism to reproduce the entropy of the extremal charged BTZ black hole without normalization when using the dilaton gravity approach.

hep-th↗

arXiv2010

Mixmaster universe in the z=3 deformed Hořava-Lifshitz gravity

The z=3 deformed Horava-Lifshitz gravity with coupling constants ωand εleads to a nonrelativistic "mixmaster" cosmological model. The potential of theory is given by the sum of IR and UV potentials in the ADM Hamiltonian formalism. It turns out that the presence of the UV-potential cannot suppress chaotic behaviors existing in the IR-potential, which comes from curvature anisotropy.

gr-qc↗

arXiv2010

Propagations of massive graviton in the deformed Hořava-Lifshitz gravity

We study massive graviton propagations of scalar, vector, and tensor modes in the deformed Hořava-Lifshitz gravity by introducing Lorentz-violating mass term. It turns out that vector and tensor modes are massively propagating on the Minkowski spacetime background. However, adding the mass term does not cure a ghost instability in the Hořava scalar.

hep-th↗

arXiv2010

Entropic force in the presence of black hole

We derive the entropic force in the presence of the Schwarzschild black hole by using the local equipartition rule and holographic principle. On the other hand, when using the Tolman temperature, one does not arrive at the Newtonian force law.

hep-th↗

arXiv2010

Entropy of black holes in the deformed Hořava-Lifshitz gravity

We find the entropy of Kehagias-Sfetsos black hole in the deformed Hořava-Lifshitz gravity by using the first law of thermodynamics. When applying generalized uncertainty principle (GUP) to Schwarzschild black hole, the entropy $S=A/4+(π/ω)\ln(A/4)$ may be interpreted as the GUP-inspired black hole entropy. Hence, it implies that the duality in the entropy between the Kehagias-Sfetsos black hole and GUP-inspired Schwarzschild black hole is present.

hep-th↗

arXiv2009

Chiral gravitational waves from z=2 Hořava-Lifshitz gravity

We construct the chiral gravitational waves from the $z=2$ Hořava-Lifshitz gravity with gravitational Chern-Simons term in the de Sitter and Minkowski backgrounds. These gravitational waves which show a feature of the Hořava-Lifshitz gravity may be related to the generalized uncertainty principle. In addition, we find the classical and quantum IR-UV transition rules in the $z=2$ Hořava-Lifshitz gravity.

hep-th↗

arXiv2009

ADM mass and quasilocal energy of black hole in the deformed Hořava-Lifshitz gravity

Inspired by the Einstein-Born-Infeld black hole, we introduce the isolated horizon to study the Kehagias-Sfetsos (KS) black hole in the deformed Hořava-Lifshitz gravity. This is because the KS black hole is more close to the Einstein-Born-Infeld black hole than the Reissner-Nordström black hole. We find the horizon and ADM masses by using the first law of thermodynamics and the area-law entropy. The mass parameter $m$ is identified with the quasilocal energy at infinity. Accordingly, we discuss the phase transition between the KS and Schwarzschild black holes by considering the heat capacity and free energy.

hep-th↗