Related papers: Quasar variability limits on cosmological density …
We report observational upper limits on the mass-energy of the cosmological gravitational-wave background, from limits on proper motions of quasars. Gravitational waves with periods longer than the time span of observations produce a simple…
Cluster strong lensing cosmography is a promising probe of the background geometry of the Universe and several studies have emerged, thanks to the increased quality of observations using space and ground-based telescopes. For the first…
We consider the gravitational lensing produced by long cosmic strings formed in a GUT scale phase transition. We derive a formula for the deflection of photons which pass near the strings that reduces to an integral over the light cone…
Cosmic strings can arise in hidden sector models with a spontaneously broken Abelian symmetry group. We have studied the couplings of the Standard Model fields to these so-called dark strings in the companion paper. Here we survey the…
A stochastic background of gravitational waves is expected to arise from a superposition of a large number of unresolved gravitational-wave sources of astrophysical and cosmological origin. It is expected to carry unique signatures from the…
Intrinsic variations of the projected density profiles of clusters of galaxies at fixed mass are a source of uncertainty for cluster weak lensing. We present a semi-analytical model to account for this effect, based on a combination of…
We study the relative contribution of cusps and pseudocusps, on cosmic (super)strings, to the emitted bursts of gravitational waves. The gravitational wave emission in the vicinity of highly relativistic points on the string follows, for a…
Gravitational wave signatures from cosmic strings are analyzed numerically. Cosmic string networks form during phase transistions in the early universe and these networks of long cosmic strings break into loops that radiate energy in the…
We investigate the peculiar velocity field due to long cosmic strings in several cosmological models and analyse the influence of a nonscaling behaviour of the string network, which is expected in open cosmological models or models with a…
Extensive analyses of statistical strong gravitational lensing are performed based on the final Cosmic Lens All Sky Survey (CLASS) well-defined statistical sample of flat spectrum radio sources and current estimates of galaxy luminosity…
We account for particle emission and gravitational radiation from cosmic string loops to determine their effect on the loop distribution and observational signatures of strings. The effect of particle emission is that the number density of…
Using 16,421 spectra from a sample of 340 quasars ($1.62<z<3.30$) from the SDSS Reverberation Mapping Project, we present an analysis of quasar spectral variability. We confirm the intrinsic Baldwin Effect and brighter-means-bluer trends in…
Significant progress in the description of quasar variability has been recently made by employing SDSS and POSS data. Common to most studies is a fundamental assumption that photometric observations at two epochs for a large number of…
We present the first cosmological constraints from a joint analysis of galaxy clustering and galaxy-galaxy lensing using extended SubHalo Abundance Matching (SHAMe). We analyse stellar mass-selected Galaxy And Mass Assembly (GAMA) galaxy…
Global topological defects produce nonzero stress-energy throughout spacetime, and as a result can have observable gravitational influence on surrounding matter. Gravitational effects of global strings are used to place bounds on their…
We investigate the spatial clustering of galaxies around quasars at redshifts from 0.6 to 1.2 using the photometric data from Sloan Digital Sky Survey (SDSS) Stripe 82. The quasar and galaxy cross-correlation functions are measured through…
We provide a quantitative description and statistical interpretation of the optical continuum variability of quasars. The Sloan Digital Sky Survey (SDSS) has obtained repeated imaging in five UV-to-IR photometric bands for 33,881…
We explore the qualitative changes that would occur if the amplitude Q ~ 10^{-5} of cosmological density fluctuations were different. If is less than about 10^{-6}, the cosmological objects that form would have so low virial temperatures…
We use the statistics of strong gravitational lensing from the CLASS survey to impose constraints on the velocity dispersion and density profile of elliptical galaxies. This approach differs from much recent work, where the luminosity…
The cosmological implications from a new estimate of the local X-ray galaxy cluster abundance are summarized. The results are then compared to independent observations. It is suggested that `low' values for the mean cosmic matter density…