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Related papers: Particle initialization effects on Lyman-$\alpha$ …

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We present a new measurement of the Ly${\alpha}$ forest power spectrum at $1.8 < z < 3.4$ using 74 Keck/HIRES and VLT/UVES high-resolution, high-S/N quasar spectra. We developed a custom pipeline to measure the power spectrum and its…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-03 Michael Walther , Joseph F. Hennawi , Hector Hiss , Jose Oñorbe , Khee-Gan Lee , Alberto Rorai , John O'Meara

Isocurvature perturbations expected from multi-field inflation models can leave unique signatures in the early Universe, but remain weakly constrained, especially on small scales. In this work, we investigate the constraining power of…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-19 Zhenfei Qin , Hayato Shimabukuro

We compare simulations of the Lyman-alpha forest performed with two different hydrodynamical codes, Gadget-2 and Enzo. A comparison of the dark matter power spectrum for simulations run with identical initial conditions show differences of…

Astrophysics · Physics 2008-11-26 John A. Regan , Martin G. Haehnelt , Matteo Viel

We reassess constraints on the cosmological baryon density from observations of the mean decrement and power spectrum of the Lyman-alpha forest, taking into account uncertainties in all free parameters in the simplest gravitational…

Astrophysics · Physics 2009-11-06 Lam Hui , Zoltan Haiman , Matias Zaldarriaga , Tal Alexander

Current cosmological data are well-described by the Lambda-Cold Dark Matter ($\Lambda$CDM) model, which assumes adiabatic initial conditions for the primordial density perturbations. This agreement between data and theory enables strong…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-02 Matthew R. Buckley , Peizhi Du , Nicolas Fernandez , Mitchell J. Weikert

We use a large set of cosmological smoothed particle hydrodynamics (SPH) simulations to examine the effect of mass resolution and box size on synthetic Lya forest spectra at 2 \leq z \leq 5. The mass resolution requirements for the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 James S. Bolton , George D. Becker

Early dark energy models, for which the contribution to the dark energy density at high redshifts is not negligible, influence the growth of cosmic structures and could leave observable signatures that are different from the standard…

Cosmology and Nongalactic Astrophysics · Physics 2009-04-01 Jun-Qing Xia , Matteo Viel

We study the impact of setting initial conditions in numerical simulations using the standard procedure based on the Zel'dovich approximation (ZA). As it is well known from perturbation theory, ZA initial conditions have incorrect second…

Astrophysics · Physics 2009-11-11 M. Crocce , S. Pueblas , R. Scoccimarro

Models for structure formation attempt to predict the power spectrum of density perturbations in the present universe from the initial power spectrum and the nature of dark matter. Observational constraints on the power spectrum at…

Astrophysics · Physics 2007-05-23 K. Subramanian , T. Padmanabhan

The observation of space-time variations in fundamental constants would provide strong evidence for the existence of new light degrees of freedom in the theory of Nature. Robustly constraining such scenarios requires exploiting observations…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-17 Laura Lopez-Honorez , Olga Mena , Sergio Palomares-Ruiz , Pablo Villanueva-Domingo , Samuel J. Witte

A homogeneous sample of 99 moderate resolution QSO spectra at z > 1.7 were presented in Paper I, including 39 previously unpublished spectra from the Multiple Mirror Telescope. The statistics of the Lyman alpha forest were discussed. In…

Astrophysics · Physics 2009-10-31 J. Scott , J. Bechtold , A. Dobrzycki , V. Kulkarni

A key result from JWST's first cycles is that galaxy formation was well underway by $z=10$. The implications of these early galaxies for reionization are less clear, however. The CMB is one of the few windows into the ionization state of…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-28 Garett Lopez , Anson D'Aloisio , Christopher Cain

Recent cosmological tensions have rekindled the search for models beyond $\Lambda$CDM that cause a suppression of the matter power spectrum. Due to the small scales accessible to Lyman-$\alpha$ data they are an excellent additional tool to…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-26 Deanna C. Hooper , Nils Schöneberg , Riccardo Murgia , Maria Archidiacono , Julien Lesgourgues , Matteo Viel

Unveiling the thermal history of the intergalactic medium (IGM) at $4 \leq z \leq 5$ holds the potential to reveal early onset HeII reionization or lingering thermal fluctuations from HI reionization. We set out to reconstruct the IGM gas…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-10 Fahad Nasir , Prakash Gaikwad , Frederick B. Davies , James S. Bolton , Ewald Puchwein , Sarah E. I. Bosman

We derive new constraints on models of decaying and annihilating dark matter (DM) by requiring that the energy injected into the intergalactic medium (IGM) not overheat it at late times, when measurements of the Lyman-$\alpha$ forest…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-18 Hongwan Liu , Wenzer Qin , Gregory W. Ridgway , Tracy R. Slatyer

We measure the power spectrum, P_F(k,z), of the transmitted flux in the Ly-alpha forest using 3035 high redshift quasar spectra from the Sloan Digital Sky Survey. This sample is almost two orders of magnitude larger than any previously…

We present a quantitative model of Lyman-alpha (Ly-alpha) emission throughout cosmic history and determine the prospects for intensity mapping of spatial fluctuations in the Ly-alpha signal. Since i) our model assumes at z>6 the minimum…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Anthony Pullen , Olivier Dore , Jamie Bock

We use cosmological hydrodynamical simulations to assess the feasibility of constraining the thermal history of the intergalactic medium during reionisation with the Ly$\alpha$ forest at $z\simeq5$. The integrated thermal history has a…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-31 Fahad Nasir , James S. Bolton , George D. Becker

We have performed high-resolution hydrodynamic simulations of the Lyman-alpha forest in a variety of popular cold dark matter dominated cosmologies, including a low density and a vacuum-dominated model. The fluctuation amplitude of these…

Astrophysics · Physics 2009-10-31 Tom Theuns , Anthony Leonard , Joop Schaye , George Efstathiou

We calibrate here cosmological radiative transfer simulation with ATON/RAMSES with a range of measurements of the Lyman alpha opacity from QSO absorption spectra. We find the Lyman alpha opacity to be very sensitive to the exact timing of…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-23 Jonathan Chardin , Martin G. Haehnelt , Dominique Aubert , Ewald Puchwein
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