Self-gravitational corrections to the Cardy-Verlinde formula of charged BTZ black hole

The entropy of the charged BTZ black hole horizon is described by the Cardy-Verlinde formula. We then compute the self-gravitational corrections to the Cardy-Verlinde formula of the charged BTZ black hole in the context of Keski-Vakkuri, Kraus and Wilczek (KKW) analysis. The self-gravitational corrections to the entropy as given by the Cardy-Verlinde formula are found to be positive. This result provides evidence in support of the claim that the holographic bound is not universal in the framework of two-dimensional gravity models.Comment: 12 pages, minor revision, accepted for publication in MPL

Anderson Transition in Disordered Bilayer Graphene

Employing the Kernel Polynomial method (KPM), we study the electronic properties of the graphene bilayers in the presence of diagonal disorder, within the tight-binding approximation. The KPM method enables us to calculate local density of states (LDOS) without need to exactly diagonalize the Hamiltonian. We use the geometrical averaging of the LDOS's at different lattice sites as a criterion to distinguish the localized states from extended ones. We find that bilayer graphene undergoes Anderson metal-insulator transition at a critical value of disorder strength

Equivalence of a one-dimensional driven-diffusive system and an equilibrium two-dimensional walk model

It is known that a single product shock measure in some of one-dimensional driven-diffusive systems with nearest-neighbor interactions might evolve in time quite similar to a random walker moving on a one-dimensional lattice with reflecting boundaries. The non-equilibrium steady-state of the system in this case can be written in terms of a linear superposition of such uncorrelated shocks. Equivalently, one can write the steady-state of this system using a matrix-product approach with two-dimensional matrices. In this paper we introduce an equilibrium two-dimensional one-transit walk model and find its partition function using a transfer matrix method. We will show that there is a direct connection between the partition functions of these two systems. We will explicitly show that in the steady-state the transfer matrix of the one-transit walk model is related to the matrix representation of the algebra of the driven-diffusive model through a similarity transformation. The physical quantities are also related through the same transformation.Comment: 5 pages, 2 figures, Revte

A Model of the EGRET Source at the Galactic Center: Inverse Compton Scattering Within Sgr A East and its Halo

Continuum low-frequency radio observations of the Galactic Center reveal the presence of two prominent radio sources, Sgr A East and its surrounding Halo, containing non-thermal particle distributions with power-law indices around 2.5-3.3 and 2.4, respectively. The central 1-2 pc region is also a source of intense (stellar) UV and (dust-reprocessed) far-IR radiation that bathes these extended synchrotron-emitting structures. A recent detection of gamma-rays (2EGJ1746-2852) from within around 1 degree of the Galactic Center by EGRET onboard the Compton GRO shows that the emission from this environment extends to very high energies. We suggest that inverse Compton scatterings between the power-law electrons inferred from the radio properties of Sgr A East and its Halo, and the UV and IR photons from the nucleus, may account for the possibly diffuse gamma-ray source as well. We show that both particle distributions may be contributing to the gamma-ray emission, though their relevant strength depends on the actual physical properties (such as the magnetic field intensity) in each source. If this picture is correct, the high-energy source at the Galactic Center is extended over several arcminutes, which can be tested with thenext generation of gamma-ray and hard X-ray missions.Comment: latex, 14 pages, 3 figures (accepted for publication in ApJ

Numerical fault simulation in Himalayas with 2 D finite element method

The nature of the stress field in the Himalaya is examined by the 2D finite element method where linear elastic rheology and plain strain condition are assumed. The Mohr-Coulomb failure criterion has been adopted to analyze the relationship between stress distribution and fault formation.Two profile models are prepared and convergent displacement is imposed on them along the NE-SW horizontal direction.The convergent displacement and physical properties of the rock layer control the distribution,orientation,magnitude and intensity of the stress and fault development.According to the calculated stress pattern,thrust faults are expected to develop in the central Himalaya (model A).Normal and some thrust faults take place in the north-western Himalaya (model B).The results from our numerical experiment are in agreement with those from the seismicity and focal mechanism solution of earthquakes and also with those of M.M.Alam and D.Hayashi (Bull.Fac.Sci.Univ. Ryukyus, 73, 15, 2002) in the central Himalaya

New Hybrid Non-Dominated Sorting Differential Evolutionary Algorithm

This paper presents a new multi objective optimization algorithm with the aim of complete coverage, faster global convergence and higher solution quality. In this technique, the high-speed characteristic of particle swarm optimization (PSO) is combined with non-dominated differential evolutionary (NSDE) and an efficient multi objective optimization algorithm is created. This method posses high convergence characteristic in quite less execution times. Generating fewer populations to find the Pareto front also makes the proposed algorithm use less memory. For the purpose of performance evaluation, the algorithm is verified with four benchmarking functions on its global optimal search ability and compared with two recognized algorithm to assess its diversity. The capability of the suggested algorithm in solving practical engineering problems such as power system protection is also studied and the results are discussed in detail