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It has been recently shown that the astrophysics of reionization can be extracted from the Ly$\alpha$ forest power spectrum by marginalizing the memory of reionization over cosmological information. This impact of cosmic reionization on the…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-07 Paulo Montero-Camacho , Yuchen Liu , Yi Mao

We present a novel technique for calculating \Lya forest correlations based on cell counts. It is applied to the line lists from 7 QSOs observed at high resolution ($\Delta v<25\kms$). Two spectra (Q0055$-$259 and Q0014$+$813) appear to be…

Astrophysics · Physics 2007-05-23 François R. Bouchet , Avery Meiksin

We investigate the effect of non-Gaussianity on the reconstruction of the initial mass field from the Ly$\alpha$ forest. We show that the transmitted flux of QSO absorption spectra are highly non-Gaussian in terms of the statistics, the…

Astrophysics · Physics 2009-10-31 Long-Long Feng , Li-Zhi Fang

The angular positions of quasars are deflected by the gravitational lensing effect of foreground matter. The Lyman-alpha forest seen in the spectra of these quasars is therefore also lensed. We propose that the signature of weak…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-21 Rupert A. C. Croft , Alessandro Romeo , R. Benton Metcalf

We discuss the determination of the linear power spectrum of dark matter fluctuations from measurements of the transmitted flux Ly-alpha Forest power spectrum. We show that at most scales probed by current measurements, the flux power…

Astrophysics · Physics 2009-11-07 Matias Zaldarriaga , Roman Scoccimarro , Lam Hui

We investigate the nature of correlations in the small-scale flux statistics of the Lyman-$\alpha$ (Ly$\alpha$) forest across redshift bins. Understanding these correlations is important for unbiased cosmological and astrophysical parameter…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-13 Bhaskar Arya , Aseem Paranjape , Tirthankar Roy Choudhury

When performing cosmological inference, standard analyses of the Lyman-$\alpha$ (Ly$\alpha$) three-dimensional correlation functions only consider the information carried by the distinct peak produced by baryon acoustic oscillations (BAO).…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-14 Francesca Gerardi , Andrei Cuceu , Andreu Font-Ribera , Benjamin Joachimi , Pablo Lemos

Traditionally, spline or kernel approaches in combination with parametric estimation are used to infer the linear coefficient (fixed effects) in a partially linear mixed-effects model for repeated measurements. Using machine learning…

Methodology · Statistics 2023-04-03 Corinne Emmenegger , Peter Bühlmann

We analyze the SDSS Ly-alpha forest P_F(k,z) measurement to determine the linear theory power spectrum. Our analysis is based on fully hydrodynamic simulations, extended using hydro-PM simulations. We account for the effect of absorbers…

We present predictions for the one-point probability distribution and cumulants of the transmitted QSO flux in the high redshift Lyman-$\alpha$ Forest. We make use of the correlation between the Lyman-$\alpha$ optical depth and the…

Astrophysics · Physics 2009-10-31 Enrique Gaztanaga , Rupert A. C. Croft

Based on the empirical formulas governing the distribution of Ly-a forest absorption, we use a Monte-Carlo technique to calculate the average HeII optical depth produced by these forest lines. A substantial contribution to HeII absorption…

Astrophysics · Physics 2009-10-30 Wei Zheng , Arthur F. Davidsen , Gerard A. Kriss

Higher order clustering statistics of Ly$\alpha$ forest provide a unique probe to study non-gaussianity in Intergalactic matter distribution up to high redshifts and from large to small scales. The author presents a brief review of his work…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-27 Soumak Maitra

We describe techniques for comparing spectra extracted from cosmological simulations and observational data, using the same methodology to link Lyman-alpha properties derived from the simulations with properties derived from observational…

Astrophysics · Physics 2009-11-07 C. E. Petry , C. D. Impey , N. Katz , D. H. Weinberg , L. E. Hernquist

We present a search for spatial and redshift correlations in a 2 A resolution spectroscopic survey of the Lyman alpha forest at 2.15 < z < 3.37 toward ten QSOs concentrated within a 1-degree diameter field. We find a signal at 2.7 sigma…

Astrophysics · Physics 2009-10-31 G. M. Williger , A. Smette , C. Hazard , J. A. Baldwin , R. G. McMahon

Our goal in this paper is to test some popular dark matter models by Ly-alpha forest in QSO spectra. Recent observations of the size and velocity of Ly-alpha forest clouds have indicated that the Ly-alpha absorption is probably not given by…

Astrophysics · Physics 2009-10-28 Hongguang BI , Jian GE , Li-Zhi FANG

The complex geometry of the Ly$\alpha$ forest data has motivated the use of various two-point statistics as alternatives to the three-dimensional power spectrum ($P_{\mathrm{3D}}$), which carries cosmological information in Fourier space.…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-05 N. G. Karaçaylı , P. L. Taylor

The inference of astrophysical and cosmological properties from the Lyman-$\alpha$ forest conventionally relies on summary statistics of the transmission field that carry useful but limited information. We present a deep learning framework…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-11 Parth Nayak , Michael Walther , Daniel Gruen , Sreyas Adiraju

We forecast the prospects for cross-correlating future line intensity mapping (LIM) surveys with the current and future Ly-$\alpha$ forest data. We use large cosmological hydrodynamic simulations to model the expected emission signal for…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-03 Mahdi Qezlou , Simeon Bird , Adam Lidz , Guochao Sun , Andrew B. Newman , Gwen C. Rudie , Yueying Ni , Rupert Croft , Tiziana Di Matteo

We study and compare fitting methods for the Lyman-$\alpha$ (Ly$\alpha$) forest 3D correlation function. We use the nested sampler PolyChord and the community code picca to perform a Bayesian analysis which we compare with previous…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-29 Andrei Cuceu , Andreu Font-Ribera , Benjamin Joachimi

We propose a new method for fitting the full-shape of the Lyman-$\alpha$ (Ly$\alpha$) forest three-dimensional (3D) correlation function in order to measure the Alcock-Paczynski (AP) effect. Our method preserves the robustness of baryon…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-25 Andrei Cuceu , Andreu Font-Ribera , Benjamin Joachimi , Seshadri Nadathur