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Related papers: The Lyman-alpha Forest as a Cosmological Tool

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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

The hydrogen Ly$\alpha$ forest is an important probe of the $z>2$ Universe that is otherwise challenging to observe with galaxy redshift surveys, but this technique has traditionally been limited to 1D studies in front of bright quasars.…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-22 Khee-Gan Lee

(abridged) The flux power spectrum of the Lyman-alpha forest in quasar (QSO) absorption spectra is sensitive to a wide range of cosmological and astrophysical parameters and instrumental effects. Modelling the flux power spectrum in this…

Astrophysics · Physics 2015-06-24 Matteo Viel , Martin G. Haehnelt

The isotropy of the Lyman-alpha forest in real-space uniquely provides a measurement of cosmic geometry at z > 2. The angular diameter distance for which the correlation function along the line of sight and in the transverse direction agree…

We present new cosmological parameter constraints from the eBOSS Lyman-$\alpha$ forest survey. We use a new theoretical model and likelihood based on the PRIYA simulation suite. PRIYA is the first suite to resolve the Lyman-$\alpha$ forest…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-19 M. A. Fernandez , Simeon Bird , Ming-Feng Ho

We analyze the flux power spectrum and its covariance using simulated Lyman alpha forests. We find that pseudo-hydro techniques are good approximations of hydrodynamical simulations at high redshift. However, the pseudo-hydro techniques…

Astrophysics · Physics 2009-11-11 Hu Zhan , Romeel Dave , Daniel Eisenstein , Neal Katz

Numerical hydrodynamical simulations are used to predict the expected absorption properties of the Lyman-Alpha forest for a variety of Cold Dark Matter dominated cosmological scenarios: CHDM, OCDM, LCDM, SCDM, and tCDM. Synthetic spectra…

Astrophysics · Physics 2009-11-06 A. Meiksin , G. Bryan , M. Machacek

The Lyman-$\alpha$ forest refers to the series of absorption features observed in the spectra of distant quasars that are produced by neutral hydrogen in the intergalactic medium. Observed over a wide range of redshifts with both ground-…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-22 Jonás Chaves-Montero

The analysis of the Lyman-alpha forest of absorption lines in quasar spectra has emerged as a potentially powerful technique to constrain the linear matter power spectrum. In most previous work, the amplitude of the ionizing background was…

Astrophysics · Physics 2009-11-11 Adam Lidz , Katrin Heitmann , Lam Hui , Salman Habib , Michael Rauch , Wallace L. W. Sargent

In quintessence models, the dark energy content of the universe is described by a slowly rolling scalar field whose pressure and energy density obey an equation of state of the form p=w $\rho$; w is in general a function of time such that…

Astrophysics · Physics 2009-11-07 M. Viel , S. Matarrese , Tom Theuns , D. Munshi , Yun Wang

We present results from end-to-end simulations of observations designed to constrain the rate of change in the expansion history of the Universe using the redshift drift of the Lyman-$\alpha$ forest absorption lines along the lines-of-sight…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-19 Chenxing Dong , Anthony Gonzalez , Stephen Eikenberry , Sarik Jeram , Manunya Likamonsavad , Jochen Liske , Deno Stelter , Amanda Townsend

In this Letter we explore a version of the test of cosmological geometry proposed by Alcock and Paczynski (1979), using observations of the Lyman-alpha forest in the spectra of close quasar pairs. By comparing the correlations in absorption…

Astrophysics · Physics 2009-10-30 Lam Hui , Albert Stebbins , Scott Burles

In this paper we critically examine predictions of the Lya forest within the standard cold dark matter (SCDM) model, paying particular attention to the low end of the column-density distribution. We show in particular that the width of…

Astrophysics · Physics 2009-10-30 Greg L. Bryan , Marie Machacek , Peter Anninos , Michael L. Norman

The forest of Lyman-$\alpha$ absorption lines detected in the spectra of distant quasars encodes information on the nature and properties of dark matter and the thermodynamics of diffuse baryonic material. Its main observable -- the 1D flux…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-19 Bruno Villasenor , Brant Robertson , Piero Madau , Evan Schneider

Lyman alpha absorber correlations contain information about the underlying density distribution associated with a particular class of absorbers. As such, they provide an opportunity to independently measure the "bias" of the Lyman alpha…

Astrophysics · Physics 2016-01-27 Romeel Davé , Neal Katz , David H. Weinberg

We discuss the feasibility of measuring the cosmological metric using the redshift space correlation function of the Lya forest in multiple lines of sight, as a function of angular and velocity separation. The geometric parameter that is…

Astrophysics · Physics 2009-10-30 Patrick McDonald , Jordi Miralda-Escude

In the low density intergalactic medium (IGM) that gives rise to the Lyman-alpha forest, gas temperature and density are tightly correlated. The velocity scale of thermal broadening and the Hubble flow across the gas Jeans scale are of…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-12 Molly S. Peeples , David H. Weinberg , Romeel Davé , Mark A. Fardal , Neal Katz

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 study the statistics of the Lyman-$\alpha$ forest in a flat LCDM cosmology with the N-body + Eulerian hydrodynamics code Nyx. We produce a suite of simulations, covering the observationally relevant redshift range $2 \leq z \leq 4$. We…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-24 Zarija Lukić , Casey Stark , Peter Nugent , Martin White , Avery Meiksin , Ann Almgren

Current results from the Lyman alpha forest assume that the primordial power spectrum of density perturbations follows a simple power law form, with running. We present the first analysis of Lyman alpha data to study the effect of relaxing…

Cosmology and Nongalactic Astrophysics · Physics 2011-05-16 Simeon Bird , Hiranya V. Peiris , Matteo Viel , Licia Verde