Publications

We present the first measurements of Lyman-αα (Lyαα) forest correlations using early data from the Dark Energy Spectroscopic Instrument (DESI). We measure the auto-correlation of Lyαα absorption using 88,509 quasars at z>2z>2, and its cross-correlation with quasars using a further 147,899 tracer quasars at z≳1.77z≳1.77. Then, we fit these correlations using a 13-parameter model based on linear perturbation theory and find that it provides a good description of the data across a broad range of scales. We detect the BAO peak with a signal-to-noise ratio of 3.8σ3.8σ, and show that our measurements of the auto- and cross-correlations are fully-consistent with previous measurements by the Extended Baryon Oscillation Spectroscopic Survey (eBOSS). Even though we only use here a small fraction of the final DESI dataset, our uncertainties are only a factor of 1.7 larger than those from the final eBOSS measurement. We validate the existing analysis methods of Lyαα correlations in preparation for making a robust measurement of the BAO scale with the first year of DESI data.

This publication presents and validates the Lyman-alpha forest fluctuations in the first DESI data release. To accomplish this measurement, the continua of DESI quasars were fitted not only in the Lyman-alpha forest region but also in featureless regions to the right of the Lyman-alpha emission line, which were used for calibration.The image displays the observed flux (black) of a high-SNR DESI quasar. The different coloured lines show the expected flux for each of the regions (quasar continuum corrected by the mean absorption), for the Lyman-alpha forest region and the SIV, CIV and CIII calibration regions.For this publication, we followed the procedures designed for SDSS analyses and made necessary adaptations for the DESI pipeline. Additionally, we enhanced the weighting scheme, resulting in an improvement of over 20% in the precision of the correlation function measurement.

The Lyman-α offers a unique avenue for studying the distribution of matter in the high redshift universe and extracting precise …

We measure the expansion rate of the Universe at redshift z=2.3 from the anisotropy of Lyman-α (Lyα) forest correlations measured by …

The three-dimensional distribution of the Lyα forest has been extensively used to constrain cosmology through measurements of the …

When performing cosmological inference, standard analyses of the Lyman-α (Lyα) three-dimensional correlation functions only consider …

Observations of the Lyman-α (Lyα) forest from spectroscopic surveys such as BOSS/eBOSS, or the ongoing DESI, offer a unique window to …

Using synthetic Lyman-α forests from the Dark Energy Spectroscopic Instrument (DESI) survey, we present a study of the impact of errors …

Three-dimensional correlations of the Lyman-α (Lyα) forest and cross correlations between the Lyα forest and quasars have been measured …

We present CoLoRe, a public software package to efficiently generate synthetic realisations of multiple cosmological surveys. CoLoRe …