An Observation of Autocorrelation of Wilson Loops on Lattice

An observation of autocorrelation of Wilson loops on lattice is presented, especially for the small seperation in Markov chain. We give a possible explanation for such behavior. We also present the dependence of autocorrelation behavior on the chosen operators in this paper.Comment: 6 pages and 4 figure

Central Engine-Powered Bright X-ray Flares in Short Gamma-Ray Bursts: A Hint of Black Hole-Neutron Star Merger?

Short gamma-ray bursts may originate from the merger of double neutron stars (NS) or that of a black hole (BH) and an NS. We propose that the bright X-ray flare related to the central engine reactivity may hint a BH-NS merger, since such a merger can provide more fall-back materials and therefore a more massive accretion disk than the NS-NS merger. Based on the observed 49 short bursts with Swift/X-ray Telescope follow-up observations, we find that three bursts have bright X-ray flares, among which three flares from two bursts are probably related to the central engine reactivity. We argue that these two bursts may originate from the BH-NS merger rather than the NS-NS merger. Our suggested link between the central engine-powered bright X-ray flare and the BH-NS merger event can be checked by the future gravitational wave detections from advanced LIGO and Virgo.Comment: 15 pages, 6 figures, accepted for publication in Ap

Understanding Simulations of Thin Accretion Disks by Energy Equation

We study the fluctuations of standard thin accretion disks by linear analysis of the time-dependent energy equation together with the vertical hydrostatic equilibrium and the equation of state. We show that some of the simulation results in Hirose et al. (2009b), such as the time delay, the relationship of power spectra, and the correlation between magnetic energy and radiation energy, can be well understood by our analytic results.Comment: 13 pages, 3 figure, accepted for publication in Ap