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Related papers: Simulating the Lyman Alpha Forest

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We present an effective field theory (EFT) approach to extract fundamental cosmological parameters from the Lyman-alpha forest flux fluctuations as an alternative to the standard simulation-based techniques. As a first application, we…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-21 Mikhail M. Ivanov , Michael W. Toomey , Naim Göksel Karaçaylı

Very recently a new inversion method has been developped to analyze the intergalactic medium seen in absorption in quasar spectra (the so-called Lyman-alpha forest). This method is applied to recover the temperature of the gas and the…

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

Cosmological studies of the Lyman-Alpha (Lya) forest typically constrain parameters using two-point statistics. However, higher-order statistics, such as the three-point function (or its Fourier counterpart, the bispectrum) offer additional…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-28 Roger de Belsunce , James M. Sullivan , Patrick McDonald

We present the PRIYA suite of cosmological simulations, based on the code and hydrodynamic model of the ASTRID simulation, and designed for cosmological analyses of the Lyman-$\alpha$ forest. Our simulation suite spans a $9$-dimensional…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-04 Simeon Bird , Martin Fernandez , Ming-Feng Ho , Mahdi Qezlou , Reza Monadi , Yueying Ni , Nianyi Chen , Rupert Croft , Tiziana Di Matteo

The inference of cosmological quantities requires accurate and large hydrodynamical cosmological simulations. Unfortunately, their computational time can take millions of CPU hours for a modest coverage in cosmological scales ($\approx (100…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-03 Chotipan Boonkongkird , Guilhem Lavaux , Sebastien Peirani , Yohan Dubois , Natalia Porqueres , Eleni Tsaprazi

We compare the observed probability distribution function of the transmission in the \HI\ Lyman-alpha forest, measured from the UVES 'Large Programme' sample at redshifts z=[2,2.5,3], to results from the GIMIC cosmological simulations. Our…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Emmanuel Rollinde , Tom Theuns , Joop Schaye , Isabelle Pâris , Patrick Petitjean

We investigate the relationship between the Lyman-alpha (Lya) forest transmission in the intergalactic medium (IGM) and the environmental density of galaxies, focusing on its implications for the measurement of ionizing radiation escape…

Astrophysics of Galaxies · Physics 2025-04-24 C. Scarlata , W. Hu , M. J. Hayes , S. Taamoli , A. A. Khostovan , C. M. Casey , A. L. Faisst , J. S. Kartaltepe , Y. Lin , M. Salvato , M. Rafelski

A theory is developed which relates the observed b-parameter of a Lyman-alpha absorption line to the velocity-curvature of the corresponding peak in the optical depth fluctuation. Its relation to the traditional interpretation of b as the…

Astrophysics · Physics 2009-10-30 Lam Hui , Robert E. Rutledge

In the context of count-in-cells statistics, the joint probability distribution of the density in two concentric spherical shells is predicted from first first principle for sigmas of the order of one. The agreement with simulation is found…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Francis Bernardeau , Sandrine Codis , Christophe Pichon

We propose a new method of analysis for the \lya forest, namely to measure the 1-point and 2-point joint probability distribution of the transmitted flux. The results for a sample of seven observed quasars and from two simulations of…

We present a comprehensive analysis of high resolution hydrodynamic simulations in terms of Lyman-alpha and Lyman-beta one dimensional flux power spectra ($P_{\alpha\alpha}$ and $P_{\beta\beta}$). In particular, we focus on the behaviour…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-15 Vid Iršič , Matteo Viel

We give a comprehensive statistical description of the Lyman-alpha absorption from the intergalactic medium in a hydrodynamic simulation at redshifts 0.1-1.6, the range of redshifts covered by HST spectra of QSOs. We use the ENZO code to…

Astrophysics · Physics 2015-05-13 Pascal Paschos , Tridivesh Jena , David Tytler , David Kirkman , Michael L. Norman

In this work we study the cosmological simulations as a tool to understand the formation of large-scale structure of the universe, for this, we show the equivalence of Newtonian cosmology with Poisson gauge and we study the solution of the…

Astrophysics of Galaxies · Physics 2014-09-05 J. E. García Farieta , L. Castañeda , J. M. Tejeiro

We study the physical origin of the low-redshift Lyman alpha forest in hydrodynamic simulations of four CDM cosmologies. Our main conclusions are insensitive to the cosmological model but depend on our assumption that the UV background…

Astrophysics · Physics 2009-10-26 Romeel Dave' , Lars Hernquist , Neal Katz , David Weinberg

In this review, the formation, evolution, and decay of the large-scale structure of the Universe is discussed in the context of observational data, numerical simulations, and the Cosmological Standard Model (CSM). Problems concerning…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-04 V. N. Lukash , E. V. Mikheeva , A. M. Malinovsky

Recent studies have focused on the low-$z$ Ly$\alpha$ forest as a potential constraint on galactic feedback, as different AGN and stellar feedback models in hydrodynamic simulations produce varying intergalactic medium (IGM) statistics.…

Astrophysics of Galaxies · Physics 2025-08-26 Megan T. Tillman , Joseph N. Burchett , Blakesley Burkhart , Vikram Khaire , Sanchayeeta Borthakur

In cosmology numerical simulations of structure formation are now of central importance, as they are the sole instrument for providing detailed predictions of current cosmological models for a whole class of important constraining…

Statistical Mechanics · Physics 2009-11-13 Michael Joyce

We review the formalism and applications of non-linear perturbation theory (PT) to understanding the large-scale structure of the Universe. We first discuss the dynamics of gravitational instability, from the linear to the non-linear…

Astrophysics · Physics 2008-11-26 F. Bernardeau , S. Colombi , E. Gaztanaga , R. Scoccimarro

We present 40 fully hydrodynamical numerical simulations of the intergalactic gas that gives rise to the Ly-alpha forest. We make artificial spectra from each and measure three output parameters: the mean flux, a measure of the most common…