XMM-Newton view of MS0735+7421: the most energetic AGN outburst in a galaxy cluster

We discuss the possible cosmological effects of powerful AGN outbursts in galaxy clusters by starting from the results of an XMM-Newton observation of the supercavity cluster MS0735+7421.Comment: 6 pages, 5 figures. To appear in the Proceedings of "Heating vs. Cooling in Galaxies and Clusters of Galaxies", August 2006, Garching (Germany

The Dirac Equation Is Separable On The Dyon Black Hole Metric

Using the tetrad formalism, we carry out the separation of variables for the massive complex Dirac equation in the gravitational and electromagnetic field of a four-parameter (mass, angular momentum, electric and magnetic charges) black hole.Comment: 13 page

Uncertainties in emissions estimates of greenhouse gases and air pollutants in India and their impacts on regional air quality

Greenhouse gas and air pollutant precursor emissions have been increasing rapidly in India. Large uncertainties exist in emissions inventories and quantification of their uncertainties is essential for better understanding of the linkages among emissions and air quality, climate, and health. We use Monte Carlo methods to assess the uncertainties of the existing carbon dioxide (CO2), carbon monoxide (CO), sulfur dioxide (SO2), nitrogen oxides (NOx), and particulate matter (PM) emission estimates from four source sectors for India. We also assess differences in the existing emissions estimates within the nine subnational regions. We find large uncertainties, higher than the current estimates for all species other than CO, when all the existing emissions estimates are combined. We further assess the impact of these differences in emissions on air quality using a chemical transport model. More efforts are needed to constrain emissions, especially in the Indo-Gangetic Plain, where not only the emissions differences are high but also the simulated concentrations using different inventories. Our study highlights the importance of constraining SO2, NOx, and NH3 emissions for secondary PM concentrations

The fermion dynamical symmetry model for the even--even and even--odd nuclei in the Xe--Ba region

The even--even and even--odd nuclei $^{126}$Xe-$^{132}$Xe and $^{131}$Ba-$^{137}$Ba are shown to have a well-realized $SO_8 \supset SO_6 \supset SO_3$ fermion dynamical symmetry. Their low-lying energy levels can be described by a unified analytical expression with two (three) adjustable parameters for even--odd (even--even) nuclei that is derived from the fermion dynamical symmetry model. Analytical expressions are given for wavefunctions and for $E2$ transition rates that agree well with data. The distinction between the FDSM and IBM $SO_6$ limits is discussed. The experimentally observed suppression of the the energy levels with increasing $SO_5$ quantum number $\tau$ can be explained as a perturbation of the pairing interaction on the $SO_6$ symmetry, which leads to an $SO_5$ Pairing effect for $SO_6$ nuclei.Comment: submitted to Phys. Rev. C, LaTeX, 31 pages, 8 figures with postscript files available on request at [email protected]

Sign reversal of the Hall resistance in the mixed-state of La1.89_{1.89} Ce0.11_{0.11}CuO4_{4} and La1.89_{1.89}Ce0.11_{0.11}(Cu0.99_{0.99}Co0.01_{0.01})O4_{4} thin films

The transport properties of La$_{1.89}$Ce$_{0.11}$CuO$_{4}$(LCCO) and La$_{1.89}$Ce$_{0.11}$(Cu$_{0.99}$Co$_{0.01}$)O$_{4}$ (LCCO:Co) superconducting thin films are investigated. When the external field $\bf H$ is applied along the crystallographic c-axis, a double sign reversal of the Hall voltage in the mixed state of LCCO:Co thin films is observed whereas a single sign reversal is detected in LCCO. A double sign reversal of the Hall signal in LCCO can be recovered if the magnetic field is tilted away from the plane of the film. We find that the transition from one to two of the Hall sign reversal coincides with the change in the pinning from strong to weak. This temperature/field induced transition is caused either by the magnetic impurities in LCCO:Co or by the coupling between the pancake vortices and the in-plane Josephson vortices in LCCO. These results are in agreement with early theoretical and numerical predictions.Comment: 6 pages, 4 figures, the proceedings of VORTEX VII in Physica

Coherent information analysis of quantum channels in simple quantum systems

The coherent information concept is used to analyze a variety of simple quantum systems. Coherent information was calculated for the information decay in a two-level atom in the presence of an external resonant field, for the information exchange between two coupled two-level atoms, and for the information transfer from a two-level atom to another atom and to a photon field. The coherent information is shown to be equal to zero for all full-measurement procedures, but it completely retains its original value for quantum duplication. Transmission of information from one open subsystem to another one in the entire closed system is analyzed to learn quantum information about the forbidden atomic transition via a dipole active transition of the same atom. It is argued that coherent information can be used effectively to quantify the information channels in physical systems where quantum coherence plays an important role.Comment: 24 pages, 7 figs; Final versiob after minor changes, title changed; to be published in Phys. Rev. A, September 200

G\"{o}del black hole, closed timelike horizon, and the study of particle emissions

We show that a particle, with positive orbital angular momentum, following an outgoing null/timelike geodesic, shall never reach the closed timelike horizon (CTH) present in the $(4+1)$-dimensional rotating G\"{o}del black hole space-time. Therefore a large part of this space-time remains inaccessible to a large class of geodesic observers, depending on the conserved quantities associated with them. We discuss how this fact and the existence of the closed timelike curves present in the asymptotic region make the quantum field theoretic study of the Hawking radiation, where the asymptotic observer states are a pre-requisite, unclear. However, the semiclassical approach provides an alternative to verify the Smarr formula derived recently for the rotating G\"{o}del black hole. We present a systematic analysis of particle emissions, specifically for scalars, charged Dirac spinors and vectors, from this black hole via the semiclassical complex path method.Comment: 13 pages; minor changes, references adde

Resonant nonstationary amplification of polychromatic laser pulses and conical emission in an optically dense ensemble of neon metastable atoms

Experimental and numerical investigation of single-beam and pump-probe interaction with a resonantly absorbing dense extended medium under strong and weak field-matter coupling is presented. Significant probe beam amplification and conical emission were observed. Under relatively weak pumping and high medium density, when the condition of strong coupling between field and resonant matter is fulfilled, the probe amplification spectrum has a form of spectral doublet. Stronger pumping leads to the appearance of a single peak of the probe beam amplification at the transition frequency. The greater probe intensity results in an asymmetrical transmission spectrum with amplification at the blue wing of the absorption line and attenuation at the red one. Under high medium density, a broad band of amplification appears. Theoretical model is based on the solution of the Maxwell-Bloch equations for a two-level system. Different types of probe transmission spectra obtained are attributed to complex dynamics of a coherent medium response to broadband polychromatic radiation of a multimode dye laser.Comment: 9 pages, 13 figures, corrected, Fig.8 was changed, to be published in Phys. Rev.

Anomaly analysis of Hawking radiation from Kaluza-Klein black hole with squashed horizon

Considering gravitational and gauge anomalies at the horizon, a new method that to derive Hawking radiations from black holes has been developed by Wilczek et al. In this paper, we apply this method to non-rotating and rotating Kaluza-Klein black holes with squashed horizon, respectively. For the rotating case, we found that, after the dimensional reduction, an effective U(1) gauge field is generated by an angular isometry. The results show that the gauge current and energy-momentum tensor fluxes are exactly equivalent to Hawking radiation from the event horizon.Comment: 15 pages, no figures, the improved version, accepted by Eur. Phys. J.

Nonadiabatic approach to dimerization gap and optical absorption coefficient of the Su-Schrieffer-Heeger model

An analytical nonadiabatic approach has been developed to study the dimerization gap and the optical absorption coefficient of the Su-Schrieffer-Heeger model where the electrons interact with dispersive quantum phonons. By investigating quantitatively the effects of quantum phonon fluctuations on the gap order and the optical responses in this system, we show that the dimerization gap is much more reduced by the quantum lattice fluctuations than the optical absorption coefficient is. The calculated optical absorption coefficient and the density of states do not have the inverse-square-root singularity, but have a peak above the gap edge and there exist a significant tail below the peak. The peak of optical absorption spectrum is not directly corresponding to the dimerized gap. Our results of the optical absorption coefficient agree well with those of the experiments in both the shape and the peak position of the optical absorption spectrum.Comment: 14 pages, 7 figures. to be published in PR