496 research outputs found

    Dilemma and Quantum Battle of Sexes

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    We analysed quantum version of the game battle of sexes using a general initial quantum state. For a particular choice of initial entangled quantum state it is shown that the classical dilemma of the battle of sexes can be resolved and a unique solution of the game can be obtained.Comment: Revised, Latex, 9 pages, no figure, corresponding author's email: [email protected]

    Suzaku broad-band spectroscopy of RX J1347.5-1145: constraints on the extremely hot gas and non-thermal emission

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    We present the results from the analysis of long Suzaku observations of the most X-ray luminous galaxy cluster RX J1347.5-1145 at z=0.451. Aims: We study physical properties of the hot (~20 keV) gas clump in the south-east (SE) region discovered by the Sunyaev-Zel'dovich (SZ) effect observations, to understand the gas physics of a violent cluster merger. We also explore a signature of non-thermal emission using the hard X-ray data. Results: We find that the single-temperature model fails to reproduce the continuum emission and Fe-K lines measured by XIS simultaneously. The two-temperature model with a very hot component improves the fit, although the XIS data can only give a lower bound on its temperature. We detect the hard X-ray emission in the 12-40 keV band at the 7 sigma level; however, the significance becomes marginal when the systematic error in the background estimation is included. With the Suzaku + Chandra joint analysis, we determine the temperature of the SE excess component to be 25.3^{+6.1}_{-4.5} ^{+6.9}_{-9.5} keV (90% statistical and systematic errors), which is in an excellent agreement with the previous SZ + X-ray analysis. This is the first time that the X-ray spectroscopy alone gives a good measurement of the temperature of the hot component in the SE region, which is made possible by Suzaku's unprecedented sensitivity to the wide X-ray band. These results strongly indicate that the cluster has undergone a recent, violent merger. The spectral analysis shows that the SE component is consistent with being thermal. We find the 3 sigma upper limit on the non-thermal flux, F < 8e-12 erg s^{-1} cm^{-2} in the 12-60 keV band. Combining this limit with a recent discovery of the radio mini halo at 1.4 GHz, we find a lower limit on the strength of the intracluster magnetic field, B > 0.007 micro G.Comment: 15 pages, 13 figures. Accepted for publication in A&

    Revival-collapse phenomenon in the fluctuations of quadrature field components of the multiphoton Jaynes-Cummings model

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    In this paper we consider a system consisting of a two-level atom, initially prepared in a coherent superposition of upper and lower levels, interacting with a radiation field prepared in generalized quantum states in the framework of multiphoton Jaynes-Cummings model. For this system we show that there is a class of states for which the fluctuation factors can exhibit revival-collapse phenomenon (RCP) similar to that exhibited in the corresponding atomic inversion. This is shown not only for normal fluctuations but also for amplitude-squared fluctuations. Furthermore, apart from this class of states we generally demonstrate that the fluctuation factors associated with three-photon transition can provide RCP similar to that occurring in the atomic inversion of the one-photon transition. These are novel results and their consequence is that RCP occurred in the atomic inversion can be measured via a homodyne detector. Furthermore, we discuss the influence of the atomic relative phases on such phenomenon.Comment: 17 pages, 4 figure

    An overview of the DII-HEP Open Stack based CMS data analysis

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    An OpenStack based private cloud with the Gluster File System has been built and used with both CMS analysis and Monte Carlo simulation jobs in the Datacenter Indirection Infrastructure for Secure High Energy Physics (DII-HEP) project. On the cloud we run the ARC middleware that allows running CMS applications without changes on the job submission side. Our test results indicate that the adopted approach provides a scalable and resilient solution for managing resources without compromising on performance and high availability. To manage the virtual machines (VM) dynamically in an elastic fasion, we are testing the EMI authorization service (Argus) and the Execution Environment Service (Argus-EES). An OpenStack plugin has been developed for Argus-EES. The Host Identity Protocol (HIP) has been designed for mobile networks and it provides a secure method for IP multihoming. HIP separates the end-point identifier and locator role for IP address which increases the network availability for the applications. Our solution leverages HIP for traffic management. This presentation gives an update on the status of the work and our lessons learned in creating an OpenStack based cloud for HEP.Peer reviewe

    Traces of past activity in the Galactic Centre

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    The Milky Way centre hosts a supermassive Black Hole (BH) with a mass of ~4*10^6 M_Sun. Sgr A*, its electromagnetic counterpart, currently appears as an extremely weak source with a luminosity L~10^-9 L_Edd. The lowest known Eddington ratio BH. However, it was not always so; traces of "glorious" active periods can be found in the surrounding medium. We review here our current view of the X-ray emission from the Galactic Center (GC) and its environment, and the expected signatures (e.g. X-ray reflection) of a past flare. We discuss the history of Sgr A*'s past activity and its impact on the surrounding medium. The structure of the Central Molecular Zone (CMZ) has not changed significantly since the last active phase of Sgr A*. This relic torus provides us with the opportunity to image the structure of an AGN torus in exquisite detail.Comment: Invited refereed review. Chapter of the book: "Cosmic ray induced phenomenology in star forming environments" (eds. Olaf Reimer and Diego F. Torres

    Dynamical System Modeling of Immune Reconstitution after Allogeneic Stem Cell Transplantation Identifies Patients at Risk for Adverse Outcomes

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    AbstractSystems that evolve over time and follow mathematical laws as they evolve are called dynamical systems. Lymphocyte recovery and clinical outcomes in 41 allograft recipients conditioned using antithymocyte globulin (ATG) and 4.5-Gy total body irradiation were studied to determine if immune reconstitution could be described as a dynamical system. Survival, relapse, and graft-versus-host disease (GVHD) were not significantly different in 2 cohorts of patients receiving different doses of ATG. However, donor-derived CD3+ cell reconstitution was superior in the lower ATG dose cohort, and there were fewer instances of donor lymphocyte infusion (DLI). Lymphoid recovery was plotted in each individual over time and demonstrated 1 of 3 sigmoid growth patterns: Pattern A (n = 15) had rapid growth with high lymphocyte counts, pattern B (n = 14) had slower growth with intermediate recovery, and pattern C (n = 10) had poor lymphocyte reconstitution. There was a significant association between lymphocyte recovery patterns and both the rate of change of donor-derived CD3+ at day 30 after stem cell transplantation (SCT) and clinical outcomes. GVHD was observed more frequently with pattern A, relapse and DLI more so with pattern C, with a consequent survival advantage in patients with patterns A and B. We conclude that evaluating immune reconstitution after SCT as a dynamical system may differentiate patients at risk of adverse outcomes and allow early intervention to modulate that risk

    Open-source modelling infrastructure: Building decarbonization capacity in Canada

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    Actions that transform our energy system are the cornerstone of decarbonizing our economy but have been hindered by the ineffective interface between researchers and decision-makers in Canada. This paper begins by arguing for a more holistic perspective on energy system decarbonization modelling and exploring how insights can aid evidence-based decision making. We then respond with the development of a modelling platform that includes three core pillars: (1) a toolbox of models that together represent the integrated energy system, (2) a dataset containing the inputs required to populate those models, and (3) a visualization suite to analyze and communicate their outputs. The Spine Toolbox is leveraged to process these three components in an efficient workflow. Taken together, the platform promotes the usability of model results by fostering consistency, transparency, and timeliness. Furthermore, the epistemic limitations of energy systems modelling and implications for platform and model design, and engaging extended peer communities, are discussed. Our hope is that this platform can be a foundational resource that facilitates collaboration between energy system and decarbonization researchers, modelling teams and decision-makers, ultimately enabling the effective application of evidence-based policy

    Magnetic fields in supernova remnants and pulsar-wind nebulae

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    We review the observations of supernova remnants (SNRs) and pulsar-wind nebulae (PWNe) that give information on the strength and orientation of magnetic fields. Radio polarimetry gives the degree of order of magnetic fields, and the orientation of the ordered component. Many young shell supernova remnants show evidence for synchrotron X-ray emission. The spatial analysis of this emission suggests that magnetic fields are amplified by one to two orders of magnitude in strong shocks. Detection of several remnants in TeV gamma rays implies a lower limit on the magnetic-field strength (or a measurement, if the emission process is inverse-Compton upscattering of cosmic microwave background photons). Upper limits to GeV emission similarly provide lower limits on magnetic-field strengths. In the historical shell remnants, lower limits on B range from 25 to 1000 microGauss. Two remnants show variability of synchrotron X-ray emission with a timescale of years. If this timescale is the electron-acceleration or radiative loss timescale, magnetic fields of order 1 mG are also implied. In pulsar-wind nebulae, equipartition arguments and dynamical modeling can be used to infer magnetic-field strengths anywhere from about 5 microGauss to 1 mG. Polarized fractions are considerably higher than in SNRs, ranging to 50 or 60% in some cases; magnetic-field geometries often suggest a toroidal structure around the pulsar, but this is not universal. Viewing-angle effects undoubtedly play a role. MHD models of radio emission in shell SNRs show that different orientations of upstream magnetic field, and different assumptions about electron acceleration, predict different radio morphology. In the remnant of SN 1006, such comparisons imply a magnetic-field orientation connecting the bright limbs, with a non-negligible gradient of its strength across the remnant.Comment: 20 pages, 24 figures; to be published in SpSciRev. Minor wording change in Abstrac
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