Rong-gen Cai

Black Holes without Mass and Entropy in Lovelock Gravity (2009)

We present a class of exact analytic and static, spherically symmetric black hole solutions in the semi-classical Einstein equations with Weyl anomaly. The solutions have two branches, one is...

Transport Coefficients from Extremal Gauss-Bonnet Black Holes (2009)

We present a class of new black hole solutions in $D$-dimensional Lovelock gravity theory. The solutions have a form of direct product $\mathcal{M}^m \times \mathcal{H}^{n}$, where $D=m+n$,...

Cai, Rong-Gen, Liu, Yan, Sun, Ya-Wen

We calculate the shear viscosity of strongly coupled field theories dual to Gauss-Bonnet gravity at zero temperature with nonzero chemical potential. We find that the ratio of the shear viscosity...

Horizon Thermodynamics and Gravitational Field Equations in Horava-Lifshitz Gravity (2009)

Generalized Misner-Sharp Energy in f(R) Gravity (2009)

We explore the relationship between the first law of thermodynamics and gravitational field equation at a static, spherically symmetric black hole horizon in Ho\v{r}ava-Lifshtiz theory with/without...

Cai, Rong-Gen, Cao, Li-Ming, Hu, Ya-Peng, Ohta, Nobuyoshi

We study generalized Misner-Sharp energy in $f(R)$ gravity in a spherically symmetric spacetime. We find that unlike the cases of Einstein gravity and Gauss-Bonnet gravity, the existence of the...

Entropy Perturbations in N-flation Model (2009)

Cai, Rong-Gen, Hu, Bin, Piao, Yun-Song

In this paper we study the entropy perturbations in the N-flation model by using the $\d\ma{N}$ formalism. We calculate the entropy corrections to the power spectrum of the overall curvature...

A Lifshitz Black Hole in Four Dimensional R^2 Gravity (2009)

Cai, Rong-Gen, Liu, Yan, Sun, Ya-Wen

We consider a higher derivative gravity theory in four dimensions with a negative cosmological constant and show that vacuum solutions of both Lifshitz type and Schr\"{o}dinger type with arbitrary...

Observational constraint on dynamical evolution of dark energy (2009)

Gong, Yungui, Cai, Rong-Gen, Chen, Yun, Zhu, Zong-Hong

We use the Constitution supernova, the baryon acoustic oscillation, the cosmic microwave background, and the Hubble parameter data to analyze the evolution property of dark energy. Four redshift bins...

Critical Dimension for Stable Self-gravitating Stars in AdS (2009)

Li, Zhong-Hua, Cai, Rong-Gen

We study the self-gravitating stars with a linear equation of state, $P=a \rho$, in AdS space, where $a$ is a constant parameter. There exists a critical dimension, beyond which the stars are always...

Thermodynamics of Black Holes in Horava-Lifshitz Gravity (2009)

Dynamical Scalar Degree of Freedom in Horava-Lifshitz Gravity (2009)

By using the canonical Hamiltonian method, we obtain the mass and entropy of the black holes with general dynamical coupling constant $\lambda$ in Ho\v{r} ava-Lifshitz Gravity. Regardless of whether...

Cai, Rong-Gen, Hu, Bin, Zhang, Hong-Bo

We investigate the linear cosmological perturbations of Ho\v{r}ava-Lifshitz gravity in a FRW universe without any matter. Our results show that a new gauge invariant dynamical scalar mode emerges,...

On the z=4 Horava-Lifshitz Gravity (2009)

Cai, Rong-Gen, Liu, Yan, Sun, Ya-Wen

We consider z=4 Horava-Lifshitz gravity in both 3+1 and 4+1 dimensions. We find black hole solutions in the IR region for a kind of z=4 Horava-Lifshitz gravity which is inherited from the new massive...

Topological Black Holes in Horava-Lifshitz Gravity (2009)

Shear Viscosity from Gauss-Bonnet Gravity with a Dilaton Coupling (2009)

We find topological (charged) black holes whose horizon has an arbitrary constant scalar curvature $2k$ in Ho\v{r}ava-Lifshitz theory. Without loss of generality, one may take $k=1,0$ and -1. The...

Cai, Rong-Gen, Nie, Zhang-Yu, Ohta, Nobuyoshi, Sun, Ya-Wen

We calculate the shear viscosity of field theories with gravity duals of Gauss-Bonnet gravity with a non-trivial dilaton using AdS/CFT. We find that the dilaton filed has a non-trivial contribution...

Holography, UV/IR Relation, Causal Entropy Bound and Dark Energy (2008)

Cai, Rong-Gen, Hu, Bin, Zhang, Yi

The constraint on the total energy in a given spatial region is given from holography by the mass of a black hole which just fits in that region, which leads to an UV/IR relation: the maximal energy...

Shear Viscosity from Effective Couplings of Gravitons (2008)

Cai, Rong-Gen, Nie, Zhang-Yu, Sun, Ya-Wen

We calculate the shear viscosity of field theories with gravity duals using Kubo-formula by calculating the Green function of dual transverse gravitons and confirm that the value of the shear...

Generalized Vaidya Spacetime in Lovelock Gravity and Thermodynamics on Apparent Horizon (2008)

Cai, Rong-Gen, Cao, Li-Ming, Hu, Ya-Peng, Kim, Sang Pyo

We present a kind of generalized Vaidya solutions in a generic Lovelock gravity. This solution generalizes the simple case in Gauss-Bonnet gravity reported recently by some authors. We study the...

Hawking Radiation of Apparent Horizon in a FRW Universe (2008)

Cai, Rong-Gen, Cao, Li-Ming, Hu, Ya-Peng

Hawking radiation is an important quantum phenomenon of black hole, which is closely related to the existence of event horizon of black hole. The cosmological event horizon of de Sitter space is also...

Shear Viscosity from AdS Born-Infeld Black Holes (2008)

Cai, Rong-Gen, Sun, Ya-Wen

We calculate the shear viscosity in the frame of AdS/CFT correspondence for the field theory with a gravity dual of Einstein-Born-Infeld gravity. We find that the ratio of $\eta/s$ is still the...

Corrected Entropy-Area Relation and Modified Friedmann Equations (2008)

Cai, Rong-Gen, Cao, Li-Ming, Hu, Ya-Peng

Applying Clausius relation, $\delta Q=TdS$, to apparent horizon of a FRW universe with any spatial curvature, and assuming that the apparent horizon has temperature $T=1/(2\pi \tilde {r}_A)$, and a...

Gauss-Bonnet Term on Vacuum Decay (2008)

Cai, Rong-Gen, Hu, Bin, Koh, Seoktae

We study the effect of the Gauss-Bonnet term on vacuum decay process in the Coleman-De Luccia formalism. The Gauss-Bonnet term has an exponential coupling with the real scalar field, which appears in...

A Note on Self-gravitating Radiation in AdS Spacetime (2008)

Li, Zhong-Hua, Hu, Bin, Cai, Rong-Gen

In this paper we investigate the equilibrium self-gravitating radiation in higher dimensional, plane symmetric anti-de Sitter space. We find that there exist essential differences from the...

Quasinormal modes in the background of charged Kaluza-Klein black hole with squashed horizons (2008)

He, Xi, Wang, Bin, Cai, Rong-Gen, Lin, Chi-Yong

We study the scalar perturbation in the background of the charged Kaluza-Klein black holes with squashed horizons. We find that the position of infinite discontinuities of the heat capacities can be...

Topological Dilaton Black Holes (2008)

Rong-gen Cai, Jeong-young Ji, Kwang-Sup Soh, Typeset Using Revt, To J

In the four-dimensional spacetime, when the two-sphere of black hole event horizons is replaced by a two-dimensional hypersurface with zero or negative constant curvature, the black hole is referred...

Entropy Function and Universality of Entropy-Area Relation for Small Black Holes (2007)

Cai, Rong-Gen, Chen, Chiang-Mei, Maeda, Kei-ichi, Ohta, Nobuyoshi, Pang, Da-Wei

We discuss the entropy-area relation for the small black holes with higher curvature corrections by using the entropy function formalism and field redefinition method. We show that the entropy...

Dynamics of holographic vacuum energy in the DGP model (2007)

Wu, Xing, Cai, Rong-Gen, Zhu, Zong-Hong

We consider the evolution of the vacuum energy in the DGP model according to the holographic principle under the assumption that the relation linking the IR and UV cut-offs still holds in this...

Thermodynamics of Apparent Horizon in Brane World Scenarios (2007)

A Note on Exact Solutions and Attractor Mechanism for Non-BPS Black Holes (2007)

Applying the Clausius relation, $\delta Q=TdS$, to the apparent horizon of FRW universe in brane world scenarios, we show that an explicit entropy expression associated with the apparent horizon can...

Ultrarelativistic Limits of Boosted Dilaton Black Holes (2007)

We obtain two extremal, spherically symmetric, non-BPS black hole solutions to 4D supergravity, one of which carries D2-D6 charges and the other carries D0-D2-D4 charges. For the D2-D6 case, rather...

Rong-gen Cai, Jeong-young Ji, Kwang-Sup Soh

We investigate the ultrarelativistic limits of dilaton black holes, black p- branes (strings), multi-centered dilaton black hole solutions and black p-brane (string) solutions when the boost velocity...

Hairs on the Cosmological Horizon (2007)

Rong-Gen Cai, Jeong-young Ji, Kwang-Sup Soh

We investigate the possibility of having hairs on the cosmological horizon. The cosmological horizon shares similar properties of black hole horizons in the aspect of having hairs on the horizon. For...

Action and Entropy of Lukewarm Black Holes (2007)

Rong-gen Cai, Jeong-young Ji, Kwang-sup Soh

We calculate the Euclidean actions and the entropies of lukewarm black holes, cold black holes and ultracold solutions in the Einstein-Maxwell theory with a positive cosmological constant. We find...

Critical Behavior in Black Hole Thermodynamics (2007)

Rong-Gen Center, Rong-gen Cai

This article is devoted to showing these results in the nondilatonic black p-branes and arbitrary dimensional dilatonic black holes. The organization of this paper is as follows. In next section we...

Slowly Rotating Charged Gauss-Bonnet Black holes in AdS Spaces (2007)

Kim, Hyeong-Chan, Cai, Rong-Gen

Rotating charged Gauss-Bonnet black hole solutions in higher dimensional ($d >4$), asymptotically anti-de Sitter spacetime are obtained in the small angular momentum limit. The angular momentum,...

Hawking-Page Phase Transition of black Dp-branes and R-charged black holes with an IR Cutoff (2007)

Cai, Rong-Gen, Cao, Li-Ming, Sun, Ya-Wen

We show that the confinement-deconfinement phase transition of supersymmetric Yang-Mills theories with 16 supercharges in various dimensions can be realized through the Hawking-Page phase transition...

Cosmological Constraints on New Agegraphic Dark Energy (2007)

Age constraints on the Agegraphic Dark Energy Model (2007)

In this work, we consider the cosmological constraints on the new agegraphic dark energy (NADE) proposed in arXiv:0708.0884, by using the observational data of type Ia supernovae (SNIa), the shift...

Zhang, Yi, Li, Hui, Wu, Xing, Wei, Hao, Cai, Rong-Gen

We investigate the age constraint on the agegraphic dark energy model by using two old galaxies (LBDS 53W091 and LBDS 53W069) and the old high redshift quasar APM 08279+5255. We find that the...

A New Model of Agegraphic Dark Energy (2007)

Observational Constraints on Agegraphic Dark Energy (2007)

In this note, we propose a new model of agegraphic dark energy based on the K\'{a}rolyh\'{a}zy relation, where the time scale is chosen to be the conformal time $\eta$ of the...

Wu, Xing, Zhang, Yi, Li, Hui, Cai, Rong-Gen, Zhu, Zong-Hong

In this paper, we use the Type Ia supernova data as well as the CMB and LSS data to constrain the agegraphic dark energy model recently proposed by Cai. Due to its peculiar nature, the parameter $n$...

Statefinder Diagnostic and w-w' Analysis for the Agegraphic Dark Energy Models without and with Interaction (2007)

A Dark Energy Model Characterized by the Age of the Universe (2007)

A new dark energy model, named as ``agegraphic dark energy'', has been proposed by one of us (R. G. Cai) in arXiv:0707.4049, based on the K\'{a}rolyh\'{a}zy uncertainty relation, which arises from...

Interacting Agegraphic Dark Energy (2007)

Quantum mechanics together with general relativity leads to the K\'arolyh\'azy relation and a corresponding energy density of quantum fluctuations of space-time. Based on the energy density we...

Deconfinement Transition of AdS/QCD at ${\cal O}(\alpha'^3)$ (2007)

A new dark energy model, named "agegraphic dark energy", has been proposed recently, based on the so-called K\'{a}rolyh\'{a}zy uncertainty relation, which arises from quantum mechanics together with...

Holographic Confinement/Deconfinement Phase Transitions of AdS/QCD in Curved Spaces (2007)

We study the confinement/deconfinement phase transition of holographic AdS/QCD models by using Ricci flat $AdS_5$ black holes up to ${\cal O}(\alpha'^3)$, which corresponds to the $\lambda$ expansion...

Cai, Rong-Gen, Shock, Jonathan P.

Recently Herzog has shown that deconfinement of AdS/QCD can be realized, in the hard-wall model where the small radius region is removed in the asymptotically AdS space, via a first order...

Ricci Flat Black Holes and Hawking-Page Phase Transition in Gauss-Bonnet Gravity and Dilaton Gravity (2007)

Cai, Rong-Gen, Kim, Sang Pyo, Wang, Bin

It is well-known that there exists a Hawking-Page phase transition between a spherical AdS black hole and a thermal AdS space. The phase transition does not happen between a Ricci flat AdS black hole...

On the Entropy Function and the Attractor Mechanism for Spherically Symmetric Extremal Black Holes (2007)

The phase transition and the Quasi-Normal Modes of black Holes (2007)

In this paper we elaborate on the relation between the entropy formula of Wald and the "entropy function" method proposed by A. Sen. For spherically symmetric extremal black holes, it is shown that...

Shen, Jianyong, Wang, Bin, Lin, Chi-Yong, Cai, Rong-Gen, Su, Ru-Keng

We reexamined the argument that the quasinormal modes could be a probe of the phase transition of a topological black hole to a hairy configuration by investigating general scalar perturbations. We...

On Entropy Function for Supersymmetric Black Rings (2007)

Deep Connection Between Thermodynamics and Gravity in Gauss-Bonnet Braneworld (2007)

The entropy function for five-dimensional supersymmetric black rings, which are solutions of $U(1)^{3}$ minimal supergravity, is calculated via both on-shell and off-shell formalism. We find that at...

Sheykhi, Ahmad, Wang, Bin, Cai, Rong-Gen

We disclose the deep connection between the thermodynamics and gravity in a general braneworld model with curvature correction terms on the brane and in the bulk, respectively. We show that the...

Thermodynamical Properties of Apparent Horizon in Warped DGP Braneworld (2007)

Sheykhi, Ahmad, Wang, Bin, Cai, Rong-Gen

In this paper we first obtain Friedmann equations for the $(n-1)$-dimensional brane embedded in the $(n+1)$-dimensional bulk, with intrinsic curvature term of the brane included in the action (DGP...

Entropy Function for Non-Extremal Black Holes in String Theory (2007)

Thermodynamic Behavior of Field Equations for f(R) Gravity (2006)

We generalize the entropy function formalism to five-dimensional and four-dimensional non-extremal black holes in string theory. In the near horizon limit, these black holes have BTZ metric as part...

Akbar, M., Cai, Rong-Gen

Recently it has shown that Einstein's field equations can be rewritten into a form of the first law of thermodynamics both at event horizon of static spherically symmetric black holes and apparent...

Thermodynamics of Apparent Horizon in Brane World Scenario (2006)

Unified First Law and Thermodynamics of Apparent Horizon in FRW Universe (2006)

In this paper we discuss thermodynamics of apparent horizon of an $n$-dimensional Friedmann-Robertson-Walker (FRW) universe embedded in an $(n+1)$-dimensional AdS spacetime. By using the method of...

New interpretation of matter-antimatter asymmetry based on branes and possible observational consequences (2006)

In this paper we revisit the relation between the Friedmann equations and the first law of thermodynamics. We find that the unified first law firstly proposed by Hayward to treat the "outer"trapping...

Cai, Rong-Gen, Li, Tong, Li, Xue-Qian, Wang, Xun

Motivated by the AMS project, we assume that after the Big Bang or inflation epoch, antimatter was repelled onto one brane which is separated from our brane where all the observational matter...

Thermodynamic Behavior of Friedmann Equation at Apparent Horizon of FRW Universe (2006)

Akbar, M., Cai, Rong-Gen

It is shown that the differential form of Friedmann equation of a FRW universe can be rewritten as a universal form $dE = TdS + WdV$ at apparent horizon, where $E$ and $V$ are the matter energy and...

Two 3-Branes in Randall-Sundrum Setup and Current Acceleration of the Universe (2006)

Wang, Anzhong, Cai, Rong-Gen, Santos, N. O.

Five-dimensional spacetimes of two orbifold 3-branes are studied, by assuming that {\em the two 3-branes are spatially homogeneous, isotropic, and independent of time}, following the so-called...

Cheng-Weyl Vector Field and its Cosmological Application (2006)

Entropy Function for 4-Charge Extremal Black Holes in Type IIA Superstring Theory (2006)

Weyl's idea on scale invariance was resurrected by Cheng in 1988. The requirement of local scale invariance leads to a completely new vector field, which we call the ``Cheng-Weyl vector field''. The...

Black Holes in Pure Lovelock Gravities (2006)

We calculate the entropy of 4-charge extremal black holes in Type IIA supersting theory by using Sen's entropy function method. Using the low energy effective actions in both $10D$ and 4D, we find...

Mass and Thermodynamics of Kaluza-Klein Black Holes with Squashed Horizons (2006)

The Lovelock gravity is a fascinating extension of general relativity, whose action consists of the dimensionally extended Euler densities. Compared to other higher order derivative gravity theories,...

Interacting Vector-like Dark Energy, the First and Second Cosmological Coincidence Problems (2006)

Recently a five-dimensional Kaluza-Klein black hole solution with squashed horizon has been found in hep-th/0510094. The black hole spacetime is asymptotically locally flat and has a spatial infinity...

Friedmann Equations of FRW Universe in Scalar-tensor Gravity, f(R) Gravity and First Law of Thermodynamics (2006)

One of the puzzles of the dark energy problem is the (first) cosmological coincidence problem, namely, {\em why does our universe begin the accelerated expansion recently? why are we living in an...

Akbar, M., Cai, Rong-Gen

In the paper, hep-th/0501055 (R.G. Cai and S.P. Kim, JHEP {\bf 0502}, 050 (2005)), it is shown that by applying the first law of thermodynamics to the apparent horizon of an FRW universe and assuming...

Conserved Charges in Even Dimensional Asymptotically locally Anti-de Sitter Space-times (2006)

Holography and D3-branes in Melvin Universes (2006)

Based on the recent paper hep-th/0503045, we derive a formula of calculating conserved charges in even dimensional asymptotically {\it locally} anti-de Sitter space-times by using the definition of...

Thermodynamic Geometry and Critical Behavior of Black Holes (2005)

Recently,in a paper hep-th/0511197, it was found that non-commutative super Yang-Mills (NCSYM) theory with space-dependent noncommutativity can be formulated as a decoupling limit of open strings...

Shen, Jianyong, Cai, Rong-Gen, Wang, Bin, Su, Ru-Keng

Based on the observations that there exists an analogy between the Reissner-Nordstr\"om-anti-de Sitter (RN-AdS) black holes and the van der Waals-Maxwell liquid-gas system, in which a correspondence...

A Note on Crossing the Phantom Divide in Hybrid Dark Energy Model (2005)

Super-acceleration on the Brane by Energy Flow from the Bulk (2005)

Recently a lot of attention has been given to building dark energy models in which the equation-of-state parameter $w$ can cross the phantom divide $w=-1$. However, to our knowledge, these models...

Cai, Rong-Gen, Gong, Yungui, Wang, Bin

We consider a brane cosmological model with energy exchange between brane and bulk. Parameterizing the energy exchange term by the scale factor and Hubble parameter, we are able to exactly solve the...

Dark Energy: relating the evolution of the universe from the past to the future (2005)

Huang, Zhuo-Yi, Wang, Bin, Cai, Rong-Gen, Su, Ru-Keng

Using the evolution history of the universe, one can make constraint on the parameter space of dynamic dark energy models. We discuss two different parameterized dark energy models. Our results...

An alternative explanation of the conflict between 1/R gravity and solar system tests (2005)

Shao, Cheng-Gang, Cai, Rong-Gen, Wang, Bin, Su, Ru-Keng

Recently the 1/R gravity has been proposed in order to explain the accelerated expansion of the universe. However, it was argued that the 1/R gravity conflicts with solar system tests. While this...

Cosmological Evolution of Hessence Dark Energy and Avoidance of the Big Rip (2005)

Crossing w=-1 in Gauss-Bonnet Brane World with Induced Gravity (2005)

Recently, many dark energy models whose equation-of-state parameter can cross the phantom divide $w_{de}=-1$ have been proposed. In a previous paper [Class. Quant. Grav. {\bf 22}, 3189 (2005);...

Cai, Rong-Gen, Zhang, Hong-Sheng, Wang, Anzhong

Recent type Ia supernovas data seemingly favor a dark energy model whose equation of state $w(z)$ crosses -1 very recently, which is a much more amazing problem than the acceleration of the universe....

Thermodynamics of Dual CFTs for Kerr-AdS Black Holes (2005)

Cai, Rong-Gen, Cao, Li-Ming, Pang, Da-Wei

Recently Gibbons {\it et al.} in hep-th/0408217 defined a set of conserved quantities for Kerr-AdS black holes with the maximal number of rotation parameters in arbitrary dimension. This set of...

Black Hole Formation from Collapsing Dust Fluid in a Background of Dark Energy (2005)

Classification of Cosmological Trajectories (2005)

The gravitational collapse of a spherically symmetric star, made of a dust fluid, $\rho_{DM}$, in a background of dark energy, $p = w\rho,\; (w < -1/3)$, is studied. It is found that when only dark...

Guo, Qi, Cai, Rong-Gen

In the context of effective Friedmann equation we classify the cosmologies in multi-scalar models with an arbitrary scalar potential $V$ according to their geometric properties. It is shown that all...

Friedmann cosmology on codimension 2 brane with time dependent tension (2005)

Zhang, Hongsheng, Guo, Qi, Cai, Rong-Gen

A solution of codimension 2 brane is found for which 4 dimensional Friedmann cosmology is recovered on the brane with time dependent tension, in the Einstein frame. The effective parameter $p/\rho$...

Hessence: A New View of Quintom Dark Energy (2005)

Wei, Hao, Cai, Rong-Gen, Zeng, Ding-Fang

Recently a lot of attention has been drawn to build dark energy model in which the equation-of-state parameter $w$ can cross the phantom divide $w=-1$. One of models to realize crossing the phantom...

First Law of Thermodynamics and Friedmann Equations of Friedmann-Robertson-Walker Universe (2005)

Cai, Rong-Gen, Kim, Sang Pyo

Applying the first law of thermodynamics to the apparent horizon of a Friedmann-Robertson-Walker universe and assuming the geometric entropy given by a quarter of the apparent horizon area, we derive...

Cosmological Evolution of Interacting Phantom Energy with Dark Matter (2004)

Guo, Zong-Kuan, Cai, Rong-Gen, Zhang, Yuan-Zhong

We investigate the cosmological evolution of an interacting phantom energy model in which the phantom field has interaction with the dark matter. We discuss the existence and stability of scaling...

K-Chameleon and the Coincidence Problem (2004)

Cosmology with Interaction between Phantom Dark Energy and Dark Matter and the Coincidence Problem (2004)

In this paper we present a hybrid model of k-essence and chameleon, named as k-chameleon. In this model, due to the chameleon mechanism, the directly strong coupling between the k-chameleon field and...

Born-Infeld Black Holes in (A)dS Spaces (2004)

We study a cosmological model in which phantom dark energy is coupled to dark matter by phenomenologically introducing a coupled term to the equations of motion of dark energy and dark matter. This...

Cai, Rong-Gen, Pang, Da-Wei, Wang, Anzhong

We study some exact solutions in a $D(\ge4)$-dimensional Einstein-Born-Infeld theory with a cosmological constant. These solutions are asymptotically de Sitter or anti-de Sitter, depending on the...

Acoustic Wormholes (2004)

Nandi, Kamal Kanti, Zhang, Yuan-Zhong, Cai, Rong-Gen

Acoustic analogs of static, spherically symmetric massive traversable Lorentzian wormholes are constructed as a {\em formal} extension of acoustic black holes. The method is straightforward but the...

Second-Order Corrections to the Power Spectrum in the Slow-Roll Expansion with a Time-Dependent Sound Speed (2004)

Wei, Hao, Cai, Rong-Gen, Wang, Anzhong

We extend Green's function method developed by Stewart and Gong to calculate the power spectrum of density perturbation in the case with a time-dependent sound speed, and explicitly give the power...

Generalized Milne Space, Eternal Accelerating Cosmology, Ep-branes and dS/CFT Correspondence (2004)

Thermodynamics and Stability of Hyperbolic Charged Black Holes (2004)

This paper has been withdrawn by the authors due to the existence of main results in the literature.

Non-asymptotically AdS/dS Solutions and Their Higher Dimensional Origins (2004)

In AdS space the black hole horizon can be a hypersurface with a positive, zero or negative constant curvature, resulting in different horizon topology. Thermodynamics and stability of black holes in...

Inflation on a Warped Dvali-Gabadadze-Porrati Brane (2004)

We look for and analyze in some details some exact solutions of Einstein-Maxwell-dilaton gravity with one or two Liouville-type dilaton potential(s) in an arbitrary dimension. Such a theory could be...

Cai, Rong-Gen, Zhang, Hongsheng

We discuss an inflation model, in which the inflation is driven by a single scalar field with exponential potential on a warped DGP brane. In contrast to the power law inflation in standard model, we...

A Note on Curvature Fluctuation of Noncommutative Inflation (2004)

Holography, the Cosmological Constant and the Upper Limit of the Number of e-foldings (2003)

An elegant approach, which incorporates the effect of the stringy spacetime uncertainty relation, to calculate power spectra of fluctuations during inflation has been suggested by Brandenberger and...

A Note on Thermodynamics of Black Holes in Lovelock Gravity (2003)

If the source of the current accelerating expansion of the universe is a positive cosmological constant, Banks and Fischler argued that there exists an upper limit of the total number of e-foldings...

Gauss-Bonnet Black Holes in dS Spaces (2003)

The Lovelock gravity consists of the dimensionally extended Euler densities. The geometry and horizon structure of black hole solutions could be quite complicated in this gravity, however, we find...

Cai, Rong-Gen, Guo, Qi

We study the thermodynamic properties associated with black hole horizon and cosmological horizon for the Gauss-Bonnet solution in de Sitter space. When the Gauss-Bonnet coefficient is positive, a...

Cosmological Scaling Solutions and Cross-coupling Exponential Potential (2003)

Guo, Zong-Kuan, Piao, Yun-Song, Cai, Rong-Gen, Zhang, Yuan-Zhong

We present a phase-space analysis of cosmology containing multiple scalar fields with a positive or negative cross-coupling exponential potential. We show that there exist power-law...

Boosted Domain Wall and Charged Kaigorodov Space (2003)

Inflationary Attractor from Tachyonic Matter (2003)

The Kaigorodov space is a homogeneous Einstein space and it describes a pp-wave propagating in anti-de Sitter space. It is conjectured in the literature that M-theory or string theory on the...

Guo, Zong-Kuan, Piao, Yun-Song, Cai, Rong-Gen, Zhang, Yuan-Zhong

We study the complete evolution of a flat and homogeneous universe dominated by tachyonic matter. We demonstrate the attractor behaviour of the tachyonic inflation using the Hamilton-Jacobi...

Holography and Entropy Bounds in Gauss-Bonnet Gravity (2002)

Cai, Rong-Gen, Myung, Yun Soo

We discuss the holography and entropy bounds in Gauss-Bonnet gravity theory. By applying a Geroch process to an arbitrary spherically symmetric black hole, we show that the Bekenstein entropy bound...

Holography in a Radiation-dominated Universe with a Positive Cosmological Constant (2002)

Cai, Rong-Gen, Myung, Yun Soo

We discuss the holographic principle in a radiation-dominated, closed Friedmann-Robertson-Walker (FRW) universe with a positive cosmological constant. By introducing a cosmological D-bound on the...

NCOS and D-branes in Time-dependent Backgrounds (2002)

Cai, Rong-Gen, Lu, Jian-Xin, Ohta, Nobuyoshi

We study noncommutative open string (NCOS) theories realized in string theory with time-dependent backgrounds. Starting from a noncommutative Yang-Mills theory (NCYM) with a constant space-space...

Assisted Tachyonic Inflation (2002)

Piao, Yun-Song, Cai, Rong-Gen, Zhang, Xinmin, Zhang, Yuan-Zhong

The model of inflation with a single tachyon field generates larger anisotropy and has difficulties in describing the formation of the Universe . In this paper we consider a model with multi tachyon...

A Note on the Positive Constant Curvature Space (2002)

The Effect of 4D Effective Cosmological Constant On The Stability of Randall-Sundrum Scenario (2002)

We construct a positive constant curvature space by identifying some points along a Killing vector in a de Sitter Space. This space is the counterpart of the three-dimensional Schwarzschild-de Sitter...

Piao, Yun-Song, Cai, Rong-Gen, Zhang, Xinmin

We study the Randall-Sundrum model with a small 4D effective cosmological constant on the brane, and drive a corrected radion potential following the Goldberger-Wise mechanism. We then discuss the...

Constant Curvature Black Hole and Dual Field Theory (2002)

Cardy-Verlinde Formula and Thermodynamics of Black Holes in de Sitter Spaces (2001)

We consider a five-dimensional constant curvature black hole, which is constructed by identifying some points along a Killing vector in a five-dimensional AdS space. The black hole has the topology...

Cardy-Verlinde Formula and Asymptotically de Sitter Spaces (2001)

We continue the study of thermodynamics of black holes in de Sitter spaces. In a previous paper (hep-th/0111093), we have shown that the entropy of cosmological horizon in the Schwarzschild-de Sitter...

Check of the Mass Bound Conjecture in the de Sitter Space (2001)

In this paper we discuss the question of whether the entropy of cosmological horizon in some asymptotically de Sitter spaces can be described by the Cardy-Verlinde formula, which is supposed to be an...

Cai, Rong-Gen, Myung, Yun Soo, Zhang, Yuan-Zhong

Recently an interesting conjecture was put forward which states that any asymptotically de Sitter space whose mass exceeds that of exact de Sitter space contains a cosmological singularity. In order...

Gauss-Bonnet Black Holes in AdS Spaces (2001)

Superluminal Noncommutative Photons (2001)

We study thermodynamic properties and phase structures of topological black holes in Einstein theory with a Gauss-Bonnet term and a negative cosmological constant. The event horizon of these...

Holography and Brane Cosmology in Domain Wall Backgrounds (2001)

With the help of the Seiberg-Witten map, one can obtain an effective action of a deformed QED from a noncommutative QED. Starting from the deformed QED, we investigate the propagation of photons in...

Cai, Rong-Gen, Zhang, Yuan-Zhong

We consider a class of domain-wall black hole solutions in the dilaton gravity with a Liouville-type dilaton potential. Using the surface counterterm approach we calculate the stress-energy tensor of...

Bekenstein Bound, Holography and Brane Cosmology in Charged Black Hole Backgrounds (2001)

Cai, Rong-Gen, Myung, Yun Soo, Ohta, Nobuyoshi

We obtain a Bekenstein entropy bound for the charged objects in arbitrary dimensions ($D\ge 4$) using the D-bound recently proposed by Bousso. With the help of thermodynamics of CFTs corresponding to...

Cardy-Verlinde Formula and AdS Black Holes (2001)

OM Theory and V-duality (2001)

In a recent paper hep-th/0008140 by E. Verlinde, an interesting formula has been put forward, which relates the entropy of a conformal formal field in arbitrary dimensions to its total energy and...

Cai, Rong-Gen, Ohta, Nobuyoshi, Lu, Jianxin, Roy, Shibaji, Wu, Yong-Shi

We show that the (M5, M2, M 2′, MW) bound state solution of eleven-dimensional supergravity recently constructed in hep-th/0009147 is related to the (M5, M2) bound state one by a finite Lorentz...

Lorentz Transformation and Light-Like Noncommutative SYM (2000)

(F1, D1, D3) Bound State, Its Scaling Limits and SL(2,Z) Duality (2000)

We show that combining the spatial noncommutative SYM limit and Lorentz transformation, one can obtain a well-behaved light-like noncommutative SYM limit. The light-like noncommutative SYM is...

Noncommutative and Ordinary Super Yang-Mills on (D$(p-2)$, D$p$) Bound States (2000)

We discuss the properties of the bound state (F1, D1, D3) in IIB supergravity in three different scaling limits and the $SL(2,{\bf Z})$ transformation of the resulting theories. In the simple...

M-brane interpolations and (2, 0) renormalization group flow (2000)

We study properties of (D$(p-2)$, D$p$) nonthreshold bound states ($2 \le p \le 6 $) in the dual gravity description. These bound states can be viewed as D$p$-branes with a nonzero NS $B$ field of...

Townsend, Paul K., Ohta, Nobuyoshi, Cai, Rong-Gen, Bergshoeff, Eric

We obtain the M5-M2-MW bound state solutions of 11-dimensional supergravity corresponding to the 1/2 supersymmetric vacua of the M5-brane equations with constant background fields. In the...

Surface counterterms and boundary stress-energy tensors for asymptotically non-anti-de Sitter spaces (1999)

Late-time evolution of the Yang-Mills field in the spherically symmetric gravitational collapse (1999)

For spaces which are not asymptotically anti-de Sitter where the asymptotic behavior is deformed by replacing the cosmological constant by a dilaton scalar potential, we show that it is possible to...

On the Thermodynamics of Large N Noncommutative Super Yang-Mills Theory (1999)

We investigate the late-time evolution of the Yang-Mills field in the self-gravitating backgrounds: Schwarzschild and Reissner-Nordstr\"om spacetimes. The late-time power-law tails develop in the...

Dynamics and thermodynamics of a probe brane in the multicenter and rotating D3-brane background (1999)

We study the thermodynamics of the large N noncommutative super Yang-Mills theory in the strong 't Hooft coupling limit in the spirit of AdS/CFT correspondence. It has already been noticed that some...

Null particle solutions in three-dimensional (anti-) de Sitter spaces (1999)

We study the dynamics and thermodynamics of a probe D3-brane in the rotating D3-brane background and in its extremal limit, which is a multicenter configuration of D3-branes distributed uniformly on...

Cai, Rong-Gen, Griffiths, J. B.

We obtain a class of exact solutions representing null particles moving in three-dimensional (anti-) de Sitter spaces by boosting the corresponding static point source solutions given by Deser and...

Localization Instability in the Rotating D-branes (1999)

Cai, Rong-Gen, Park, Dahl, Soh, Kwang-Sup

In the microcanonical ensemble for string theory on $ AdS_m \times S^n$, there is a phase transition between a black hole solution extended over the $S^n$ and a solution localized on the $S^n$ if the...

Critical behavior in black hole thermodynamics (1999)

Null particle solutions in three-dimensional (anti-) de Sitter spaces (1999)

In this talk I introduce the critical behavior occurring at the extremal limit of black holes. The extremal limit of black holes is a critical point and a phase transition takes place from the...

Rong-Gen Cai, J. B. Griffiths

We obtain a class of exact solutions representing null particles moving in three-dimensional (anti-) de Sitter spaces by boosting the corresponding static point source solutions given by Deser and...

Critical Behavior in the Rotating D-branes (1998)

Cai, Rong-Gen, Soh, Kwang-Sup

The low energy excitation of the rotating D3-branes is thermodynamically stable up to a critical angular momentum density. This indicates that there is a corresponding phase transition of the ${\cal...

Stability of degenerate Cauchy horizons in black hole spacetimes (1998)

Topological black holes in the dimensionally continued gravity (1998)

In the multihorizon black hole spacetimes, it is possible that there are degenerate Cauchy horizons with vanishing surface gravities. We investigate the stability of the degenerate Cauchy horizon in...

Cai, Rong-Gen, Soh, Kwang-Sup

We investigate the topological black holes in a special class of Lovelock gravity. In the odd dimensions, the action is the Chern-Simons form for the anti-de Sitter group. In the even dimensions, it...

Thermodynamic Curvature of the BTZ Black Hole (1998)

Cai, Rong-Gen, Cho, Jin-Ho

Some thermodynamic properties of the Ba\~nados-Teitelboim-Zanelli (BTZ) black hole are studied to get the effective dimension of its corresponding statistical model. For this purpose, we make use of...

Ultrarelativistic limits of boosted dilaton black holes (1998)

Cai, Rong-Gen, Ji, Jeong-Young, Soh, Kwang-Sup

We investigate the ultrarelativistic limits of dilaton black holes, black $p$-branes (strings), multi-centered dilaton black hole solutions and black $p$-brane (string) solutions when the boost...

Propagation of vacuum polarized photons in topological black hole spacetimes (1998)

Electromagnetic fields in a 3D cavity and in a waveguide with oscillating walls (1997)

The one-loop effective action for QED in curved spacetime contains equivalence principle violating interactions between the electromagnetic field and the spacetime curvature. These interactions lead...

Ji, Jeong-Young, Soh, Kwang-Sup, Cai, Rong-Gen, Kim, Sang Pyo

We consider classical and quantum electromagnetic fields in a three-dimensional (3D) cavity and in a waveguide with oscillating boundaries of the frequency $\Omega $. The photons created by the...

Action and entropy of black holes in spacetimes with a cosmological constant (1997)

Cai, Rong-Gen, Ji, Jeong-Young, Soh, Kwang-Sup

In the Euclidean path integral approach, we calculate the actions and the entropies for the Reissner-Nordstr\"om-de Sitter solutions. When the temperatures of black hole and cosmological horizons are...

Topological dilaton black holes (1997)

Cai, Rong-Gen, Ji, Jeong-Young, Soh, Kwang-Sup

In four-dimensional spacetime, when the two-sphere of black hole event horizons is replaced by a two-dimensional hypersurface with zero or negative constant curvature, the black hole is referred to...

Hairs on the cosmological horizon (1997)

Cai, Rong-Gen, Ji, Jeong-Young

We investigate the possibility of having hairs on the cosmological horizon. The cosmological horizon shares similar properties of black hole horizons in the aspect of having hairs on the horizons....

Critical behavior for the dilaton black holes (1997)

Cai, Rong-Gen, Myung, Y. S.

We study the critical behavior in the black p-branes and four dimensional charged dilaton black holes. We calculate the thermodynamic fluctuations in the various (microcanonical, canonical, and...

Black holes in the Brans-Dicke-Maxwell theory (1997)

Cai, Rong-Gen, Myung, Y. S.

The black hole solutions in the higher dimensional Brans-Dicke-Maxwell theory are investigated. We find that the presence of the nontrivial scalar field depends on the spacetime dimensions (D). When...

Effective spatial dimension of extremal non-dilatonic black p-branes and the description of entropy on the world volume (1997)