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  1. Abstract

    Over the next 10 years, the Vera C. Rubin Observatory (Rubin) will observe ∼10 million active galactic nuclei (AGNs) with a regular and high cadence. During this time, the intensities of most of these AGNs will fluctuate stochastically. Here, we explore the prospects to quantify precisely these fluctuations with Rubin measurements of AGN light curves. To do so, we suppose that each light curve is described by a damped random walk with a given fluctuation amplitude and correlation time. Theoretical arguments and some current measurements suggest that the correlation timescale and fluctuation amplitude for each AGN may be correlated with other observables. We use an expected-information analysis to calculate the precision with which these parameters will be inferred from the measured light curves. We find that the measurements will be so precise as to allow the AGNs to be separated into up to ∼10 different correlation-timescale bins. We then show that if the correlation time varies as some power of the luminosity, the normalization and power-law index of that relation will be determined to(104%). These results suggest that with Rubin, precisely measured variability parameters will take their place alongside spectroscopy in the detailed characterization of individual AGNs and in the study of AGN population statistics. Analogous analyses will be enabled by other time-domain projects, such as CMB-S4.

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  4. A bstract We consider the scattering of high energy and ultra relativistic spherically symmetric shells in asymptotically AdS D spacetimes. We analyze an exclusive amplitude where a single spherically symmetric shell goes in and a single one comes out, such that the two have different global symmetry charges of the effective gravity theory. We study a simple wormhole configuration that computes the square of the amplitude and analyze its properties. 
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    Free, publicly-accessible full text available April 1, 2024
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  7. A bstract We construct large classes of non-BPS smooth horizonless geometries that are asymptotic to AdS 3 × S 3 × T 4 in type IIB supergravity. These geometries are supported by electromagnetic flux corresponding to D1-D5 charges. We show that Einstein equations for systems with eight commuting Killing vectors decompose into a set of Ernst equations, thereby admitting an integrable structure. This feature, which can a priori be applied to other $$ {\textrm{AdS}}_D\times \mathcal{C} $$ AdS D × C settings in supergravity, allows us to use solution-generating techniques associated with the Ernst formalism. We explicitly derive solutions by applying the charged Weyl formalism that we have previously developed. These are sourced internally by a chain of bolts that correspond to regions where the orbits of the commuting Killing vectors collapse smoothly. We show that these geometries can be interpreted as non-BPS T 4 and S 3 deformations on global AdS 3 × S 3 × T 4 that are located at the center of AdS 3 . These non-BPS deformations can be made arbitrarily small and should therefore correspond to non-supersymmetric operators in the D1-D5 CFT. Finally, we also construct interesting bound states of non-extremal BTZ black holes connected by regular bolts. 
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    Free, publicly-accessible full text available February 1, 2024
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