17090886
Rms–flux relation of Cyg X-1 with RXTE: dipping and nondipping cases
Abstract
The rms (root mean square) variability is the parameter for understanding the emission temporal properties of X-ray binaries (XRBs) and active galactic nuclei (AGN). The rms–flux relation with Rossi X-ray Timing Explorer (RXTE) data for the dips and nondip of black hole Cyg X-1 has been investigated in this paper. Our results show that there exist the linear rms–flux relations in the frequency range 0.1–10 Hz for the dipping light curve. Moreover, this linear relation still remains during the nondip regime, but with the steeper slope than that of the dipping case in the low energy band. For the high energy band, the slopes of the dipping and nondipping cases are hardly constant within errors. The explanations of the results have been made by means of the “Propagating Perturbation” model of Lyubarskii (Lyubarskii, Y.E., Mon. Not. Roy. Astron. Soc. 292, 679–685 (1997)).

119164153
EVOLUTION OF THE CROSS-CORRELATION AND TIME LAG OF 4U 1735-44 ALONG THE BRANCHES
We analyze the cross-correlation function between the soft and hard X-rays of atoll source 4U 1735-44 with RXTE data, and find anti-correlated soft and hard time lags of about a hecto-second. In the island state, the observations do not show any obvious correlations, and most observations of the banana branch show a positive correlation. However, anti-correlations are detected in the upper banana branch. These results are different from those of Z-sources (Cyg X-2, GX 5-1), where anti-correlations are detected in the horizontal branch and upper normal branch. In this case, the lag timescales of both this atoll and Z-sources are found to be similar, at a magnitude of several tens to hundreds of seconds. As a comparison, it is noted that anti-correlated lags lasting thousands of seconds have been reported from several black hole candidates in their intermediate states. In addition, for an observation containing four segments that show positive or anti-correlation, we analyze the spectral evolution with the hybrid model. In the observation, the anti-correlation is detected at the highest flux. The fitting results show that the Comptonized component is not the lowest at the highest flux, which suggests that the anti-correlation corresponds to the transition between the soft and hard states. Finally, we compare the corresponding results of atoll source 4U 1735-44 with those observed in Z-sources and black hole candidates, and the possible origins of the anti-correlated time lags are discussed.
119217076
Scattering amplitudes in Lifshitz spacetime
AbstractWe consider the calculation of scattering amplitudes in eld theories dual to Lifshitzspacetimes. These amplitudes provide an interesting probe of the IR structure of the eldtheory; our aim is to use them to explore the observable consequences of the singularityin the spacetime. We assume the amplitudes can be related by T-duality to a Wilsonloop, as in the AdS case, and determine the bulk minimal surfaces for the simplest cuspWilson loop. We use this to determine the leading IR singularity in the amplitude. We nd there is a stronger IR singularity for z > 1 than for z = 1, with a coecient whichvanishes as z !1. 1 Introduction The application of holography to non-relativistic theories represents an interesting extension ofthe usual holographic dictionary. The simplest example of this type is the Lifshitz spacetime[1]. The geometry isds 2 = dt 2 r 2z +dr + d~x 2 r(1)where there are d s spatial dimensions ~x, and we have set the curvature scale to one for con-venience. The spacetime has an isometry under t!