Related papers: The Lyman-alpha Forest as a Cosmological Tool
Detecting the change of a cosmological object's redshift due to the time evolution of the Universal expansion rate is an ambitious experiment that will be attempted with future telescope facilities. In this paper, we describe the…
In gravitational instability models, \lya absorption arises from a continuous fluctuating medium, so that spectra provide a non-linear one-dimensional ``map'' of the underlying density field. We characterise this continuous absorption using…
We present an improved analytical model to predict the Lyman-alpha forest at the field level in redshift space from the dark matter field, expanding upon the widely-used Fluctuating Gunn-Peterson approximation (FGPA). In particular, we…
We propose a simple model for the origin and evolution of \lya clouds based on cosmological conductive/cooling fronts. In this model the \lya arises in the interfaces between the IGM and cold clouds that could be tentatively identified with…
The flux/transmission power spectrum has become a popular statistical tool in studies of the high redshift ($z > 2$) Lyman-alpha forest. At low redshifts, where the forest has thinned out into a series of well-isolated absorption lines, the…
As a result of resonant scatterings off hydrogen atoms, Lyman-alpha (Lya) emission from star-forming galaxies provides a probe of the (hardly isotropic) neutral gas environment around them. We study the effect of the environmental…
Recent numerical simulations have lead to a paradigm shift in our understanding of the intergalactic medium, and the loss of a physical justification for Voigt profile fitting of the Lyman-alpha forest. Many individual lines seen in…
It is shown how wavelets may be used to analyse the absorption properties of the Lya forest. The Discrete Wavelet Transform of a QSO spectrum is used to decompose the light fluctuations that comprise the forest into orthogonal wavelets. It…
We use the Ly-$\alpha$ Mass Association Scheme (LyMAS; Peirani et al. 2014) to predict cross-correlations at $z=2.5$ between dark matter halos and transmitted flux in the Ly-$\alpha$ forest, and compare to cross-correlations measured for…
The post-reionization thermal state of the intergalactic medium is characterized by a power-law relationship between temperature and density, with a slope determined by the parameter $\gamma$. We describe a new method to measure $\gamma$…
Lyman-alpha is now widely used to investigate the galaxy formation and evolution in the high redshift universe. However, without a rigorous understanding of the processes which regulate the Lya escape fraction, physical interpretations of…
The Lya forest has emerged as one of the few systems capable of probing small-scale structure at high-z with high precision. In this talk I highlight two areas in which the Lya forest is shedding light on fundamental questions in cosmology,…
Numerous surveys are underway or planned that aim to exploit the Lyman-alpha emission line as a probe of the distant universe. We investigate the reliability of such high-z Lya studies and the validity of the conclusions that are based upon…
Results are presented for one-dimensional numerical hydrodynamics computations of the structure and evolution of Lya forest clouds gravitationally confined by dark matter minihalos. The clouds are developed from linear perturbations at high…
Observations indicate galaxies are distributed in a filament-dominated web-like structure; classic examples are the Coma and Perseus-Pisces superclusters. Numerical experiments at high and low redshift of viable structure formation theories…
The apparent angular positions of quasars are deflected on the sky by the gravitational field sourced by foreground matter. This weak lensing effect is measurable through the distortions it introduces in the lensed quasar spectra.…
The Lyman-$\alpha$ forests observed in the spectra of high-redshift quasars can be used as a tracer of the cosmological matter density to study baryon acoustic oscillations (BAO) and the Alcock-Paczynski effect. Extraction of cosmological…
We report the first detection at a median redshift $z = 2.49$ of large-scale matter flows around cosmic voids. Voids are identified within a tomographic map of large-scale Lyman-$\alpha$ (Ly$\alpha$) transmissions, built from the eBOSS…
Using a suite of hydrodynamical simulations with cold dark matter, baryons, and neutrinos, we present a detailed study of the effect of massive neutrinos on the 1-D and 3-D flux power spectra of the Lyman-$\alpha$ (Ly$\alpha$) forest. The…
Cosmological hydrodynamic simulations can accurately predict the properties of the intergalactic medium (IGM), but only under the condition of retaining high spatial resolution necessary to resolve density fluctuations in the IGM. This…