Evolution of Bouncing Cosmological Models Due to the Self-Gravitational Corrections

A four-dimensional timelike brane with non-zero energy density is considered as the boundary of a five dimensional Schwarzschild anti de Sitter bulk background. The self-gravitational corrections to the first Friedmann equation act as a source of stiff matter contrary to standard FRW cosmology where the charge of the black hole plays this role. In a previous related paper (Setare in Eur. Phys. J. C 47:851, [2006]), bouncing cosmology was studied, from a holographic perspective, for the very special case of a brane that is void of any intrinsic matter sources. In this paper we extend the results of (Setare in Eur. Phys. J. C 47:851, [2006]). We consider the physically relevant case in which a perfect fluid with equation of state of radiation is present on the brane. Then, we describe solutions of the braneworld theory under investigation and also determine their stability. Specifically, if we do not consider the self-gravitational corrections, the AdS black hole with zero ADM mass, and open horizon is an attractor, while, if we consider, the AdS black hole with zero ADM mass and flat horizon, and D3-brane with non-zero energy density is a repeller.     

Holographic Entanglement Entropy of the BTZ Black Hole

We investigate quantum entanglement of gravitational configurations in 3D AdS gravity using the AdS/CFT correspondence. We derive explicit formulas for the holographic entanglement entropy (EE) of the BTZ black hole, conical singularities and regularized AdS₃. The leading term in the large temperature expansion of the holographic EE of the BTZ black hole reproduces exactly its Bekenstein-Hawking entropy S _BH , whereas the subleading term behaves as ln S _BH . We also show that the leading term of the holographic EE for the BTZ black hole can be obtained from the large temperature expansion of the partition function of a broad class of 2D CFTs on the torus. This result indicates that black hole EE is not a fundamental feature of the underlying theory of quantum gravity but emerges when the semiclassical notion of spacetime geometry is used to describe the black hole.     

Dilatonic Entropic Force

We show in detail that the entropic force of the static spherically symmetric spacetimes with unusual asymptotics can be calculated through the Verlinde’s arguments. We introduce three different holographic screen candidates, which are first employed thoroughly by Myung and Kim [Phys. Rev. D 81, 105012 (2010)] for Schwarzschild black hole solutions, in order to identify the entropic force arising between a charged dilaton black hole and a test particle. The significance of the dilaton parameter on the entropic force is highlighted, and shown graphically.     

Squeeze-swapping by Bell measurement studied in terms of the entangled state representation

By virtue of the entangled state representation(Hong-Yi Fan and J R Klauder 1994 Phys.Rev.A 49 704) and the two-mode squeezing operator’s natural representation(Hong-Yi Fan and Yue Fan 1996 Phys.Rev.A 54 958) we propose the squeeze-swapping mechanism which can generate quantum entanglement and new squeezed states of continuum variables.     

Security proof of counterfactual quantum cryptography against general intercept-resend attacks and its vulnerability

Counterfactual quantum cryptography,recently proposed by Noh,is featured with no transmission of signal particles.This exhibits evident security advantages,such as its immunity to the well-known photon-number-splitting attack.In this paper,the theoretical security of counterfactual quantum cryptography protocol against the general interceptresend attacks is proved by bounding the information of an eavesdropper Eve more tightly than in Yin’s proposal [Phys.Rev.A 82 042335(2010)].It is also shown that practical counterfactual quantum cryptography implementations may be vulnerable when equipped with imperfect apparatuses,by proving that a negative key rate can be achieved when Eve launches a time-shift attack based on imperfect detector efficiency.     

Particle Creation in a Robertson–Walker Universe Revisited

We reanalyze the problem of particle creation in a 3+1 spatially closed Robertson–Walker space-time. We compute the total number of particles produced by this non-stationary gravitational background as well as the corresponding total energy and find a slight discrepancy between our results and those recently obtained in the literature (Setare, M.R. in Int. J. Theor. Phys. 43:2237, 2004).     

Surface tension of superfluid helium

Summary We present here the calculation of the expression for the surface tension depression by taking into consideration the finite size of the molecular superfluid helium. The agreement between the experimental results (J. R. Eckardt, D. O. Edwards, S. Y. Shen and F. M. Gasparini:Phys. Rev. B,16, 1944 (1977)) and the theoretical results is much better than previously published (K. R. Atkins:Can. J. Phys.,31, 1165 (1953)).     

Single-oscillator model and determination of optical constants of spray pyrolyzed amorphous SnO<Subscript>2</Subscript> thin films

It has recently been shown that growth of a multilayer structure with one or more delta-layers at high temperature leads to spreading and asymmetrization of the dopant distribution [see, for example, E.F.J. Schubert, Vac. Sci. Technol. A. 8, 2980 (1990), A.M. Nazmul, S. Sugahara, M. Tanaka, J. Crystal Growth 251, 303 (2003); R.C. Newman, M.J. Ashwin, M.R. Fahy, L. Hart, S.N. Holmes, C. Roberts, X. Zhang, Phys. Rev. B 54, 8769 (1996); E.F. Schubert, J.M. Kuo, R.F. Kopf, H.S. Luftman, L.C. Hopkins, N.J. Sauer, J. Appl. Phys. 67, 1969 (1990); P.M. Zagwijn, J.F. van der Veen, E. Vlieg, A.H. Reader, D.J. Gravesteijn, J. Appl. Phys. 78, 4933 (1995); W.S. Hobson, S.J. Pearton, E.F. Schubert, G. Cabaniss, Appl. Phys. Lett. 55, 1546 (1989); Delta Doping of Semiconductors, edited by E.F. Schubert (Cambridge University Press, Cambridge, 1996); Yu.N. Drozdov, N.B. Baidus', B.N. Zvonkov, M.N. Drozdov, O.I. Khrykin, V.I. Shashkin, Semiconductors 37, 194 (2003); E. Skuras, A.R. Long, B. Vogele, M.C. Holland, C.R. Stanley, E.A. Johnson, M. van der Burgt, H. Yaguchi, J. Singleton, Phys. Rev. B 59, 10712 (1999); G. Li, C. Jagadish, Solid-State Electronics 41, 1207 (1997)]. In this work analytical and numerical analysis of dopant dynamics in a delta-doped area of a multilayer structure has been accomplished using Fick's second law. Some reasons for asymmetrization of a delta-dopant distribution are illustrated. The spreading of a delta-layer has been estimated using example materials of a multilayer structure, a delta-layer and an overlayer.     

Hidden conformal symmetry of self-dual warped AdS<Subscript>3</Subscript> black holes in topological massive gravity

We extend the recently proposal of hidden conformal symmetry to the self-dual warped AdS₃ black holes in topological massive gravity. It is shown that the wave equation of massive scalar field with sufficient small angular momentum can be reproduced by the SL(2, R) Casimir quadratic operator. Due to the periodic identification in the φ direction, it is found that only the left section of hidden conformal symmetry is broken to U(1), while the right section is unbroken, which only gives the left temperature of dual CFT. As a check of the dual CFT conjecture of self-warped AdS₃ black hole, we further compute the Bekenstein–Hawking entropy and absorption cross section and quasinormal modes of scalar field perturbation and show these are just of the forms predicted by the dual CFT.     

Main parameters of a coaxial electrostatic lens

Coaxial electrostatic lenses are used in combination with a magnetic field in plasma-optical and manometric devices [A. I. Morozov and S. V. Lebedev, in Reviews of Plasma Physics, Vol. 8, M. A. Leontovich (ed.), Consultants Bureau, New York (1980); V. P. Afanas’ev, A. A. Vydrik, L. P. Ovsyannikova, and E. V. Shpak, Sov. Phys. Tech. Phys. 25, 1049 (1980)]. Their employment in systems for transporting beams of high-energy charged particles is also known [P. Krejcik, B. V. King, and I. C. Kelly, Optik (Stuttgart) 55, 385 (1980)], since, along with quadrupole lenses, they have a large optical strength. Expressions for the trajectories of charged low-energy particles were obtained by L. P. Ovsyannikova and S. V. Pasovets [Sov. Phys. Tech. Phys. 32, 1422 (1987)] in the approximation of a rectangular field model with consideration of the variation of the energy at the entrance and exit from the field. The possibility, in principle, of focusing a parallel beam in a ring is demonstrated. Zh. Tekh. Fiz. 67, 81–82 (December 1997)     

Monte Carlo simulations of primitive models for ionic systems using the Wolf method

Thermodynamic and structural properties of primitive models for electrolyte solutions and molten salts were studied using NVT and NPT Monte Carlo simulations. The Coulombic interactions were simulated using the Wolf method [D. Wolf, Phys. Rev. Lett. 68, 3315 (1992); D. Wolf, P. Keblinnski, S. R. Phillpot, and J. Eggebrecht, J. Chem. Phys. 110, 8254 (1999)]. Results for 1?:?1 and 2?:?1 charge ratio electroneutral systems are presented, using the restricted and non-restricted primitive models, as well as a soft PM pair potential for a monovalent salt [J.-P. Hansen and I. R. McDonald, Phys. Rev. A 11, 2111 (1975)] that has also been used to model 2?:?12 and 1?:?20 asymmetric colloidal systems, with size ratios 1?:?10 and 2?:?15, respectively [B. Hribar, Y. V. Kalyuzhnyi, and V. Vlachy, Molec. Phys. 87, 1317 (1996)]. We present the predictions obtained for these systems using the Wolf method. Our results are in very good agreement with simulation data obtained with the Ewald sum method as well as with integral-equation theories results. We discuss the relevance of the Wolf method in the context of variable-ranged potentials in molecular thermodynamic theories for complex fluids.     

R-Charged Black Hole and Holographic Superfluid

In this paper we consider an interesting model of superfluid and use AdS/CFT correspondence to extract sound modes. We assume that dual picture of superfluid is the R-charged black hole with two equal charges. By using hydrodynamic variables of such a black hole we obtain first, second and fourth sound modes as a function of black hole charge.     

Fragile black holes and an angular momentum cutoff in peripheral heavy ion collisions

In collisions of heavy ions at extremely high energies, it is possible for a significant quantity of angular momentum to be deposited into the Quark–Gluon Plasma which is thought to be produced. We develop a simple geometric model of such a system, and show that it is dual, in the AdS/CFT sense, to a rotating AdS black hole with a topologically planar event horizon. However, when this black hole is embedded in string theory, it proves to be unstable, for all non-zero angular momenta, to a certain non-perturbative effect: the familiar planar black hole, as used in most AdS/CFT analyses of QGP physics, is “fragile”. The upshot is that the AdS/CFT duality apparently predicts that the QGP should always become unstable when it is produced in peripheral collisions. However, we argue that holography indicates that relatively low angular momenta delay the development of the instability, so that in practice it may be observable only for peripheral collisions involving favorable impact parameters, generating extremely large angular momenta. In principle, the result may be holographic prediction of a cutoff for the observable angular momenta of the QGP, or perhaps of an analogous phenomenon in condensed matter physics.     

Thermodynamics in rotating anti-de Sitter black holes with massive scalar field in three dimensions

We investigated the tendency in the variations of CFT₂ when a rotating AdS₃ black hole changes because of the fluxes transferred by the scattering of a massive scalar field according to the anti-de Sitter (AdS)/conformal field theory (CFT) correspondence. The conserved quantities of the black hole are definitely constrained by the extremal condition. Moreover, the laws of thermodynamics provide a direction for the changes in the conserved quantities. Therefore, the black hole cannot be extremal under the scattering; this is naturally preferred. According to the relationship between the rotating AdS₃ black hole and dual CFT₂, we find that such changes in the black hole constrain the variations in the eigenstates of dual CFT₂. Furthermore, the tendency in the variations is closely related to the laws of thermodynamics.