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Related papers: An Emulator for the Lyman-alpha Forest

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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

The Ly$\alpha$ forest, a series of HI absorption lines in the quasar spectra, is a powerful tool for probing the large-scale structure of the intergalactic medium. Its three-dimensional (3D) correlation and cross-correlations with quasars…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-23 Koichiro Nakashima , Atsushi J. Nishizawa , Kentaro Nagamine , Yuri Oku , Ikkoh Shimizu

Studying the impact of systematic effects, optimizing survey strategies, assessing tensions between different probes and exploring synergies of different data sets require a large number of simulated likelihood analyses, each of which cost…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-07 Supranta S. Boruah , Tim Eifler , Vivian Miranda , Sai Krishanth P. M

We present methods for emulating the matter power spectrum by combining information from cosmological $N$-body simulations at different resolutions. An emulator allows estimation of simulation output by interpolating across the parameter…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-17 Ming-Feng Ho , Simeon Bird , Christian R. Shelton

Maps of the large-scale structure of the Universe at redshifts 2-4 can be made with the Lyman-alpha forest which are complementary to low redshift galaxy surveys. We apply the Wiener interpolation method of Caucci et al. to construct…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-08 Melih Ozbek , Rupert A. C. Croft , Nishikanta Khandai

The 1D Ly-$\alpha$ forest flux power spectrum $P_{\mathrm{1D}}$ is sensitive to scales smaller than a typical galaxy survey, and hence ties to the intergalactic medium's thermal state, suppression from neutrino masses and new dark matter…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-17 Naim Göksel Karaçaylı , Andreu Font-Ribera , Nikhil Padmanabhan

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

Observations of the Lyman-$\alpha$ (Ly$\alpha$) forest from spectroscopic surveys such as BOSS/eBOSS, or the ongoing DESI, offer a unique window to study the growth of structure on megaparsec scales. Interpretation of these measurements is…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-09 Christian Pedersen , Andreu Font-Ribera , Nickolay Y. Gnedin

Lyman-$\alpha$(Ly$\alpha$) forest in the spectra of distant quasars encodes the information of the underlying cosmic density field at smallest scales. The modelling of the upcoming large and high-fidelity forest data using cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-10 Bhaskar Arya

This work presents a new physically-motivated supervised machine learning method, Hydro-BAM, to reproduce the three-dimensional Lyman-$\alpha$ forest field in real and in redshift space learning from a reference hydrodynamic simulation,…

Small-scale correlations measured in the Lyman-$\alpha$ (Ly$\alpha$) forest encode information about the intergalactic medium and the primordial matter power spectrum. In this article, we present and implement a simple method to measure the…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-27 Marie Lynn Abdul-Karim , Eric Armengaud , Guillaume Mention , Solène Chabanier , Corentin Ravoux , Zarija Lukić

The Lyman-$\alpha$ forest is a valuable probe of dark matter models featuring a scale-dependent suppression of the power spectrum as compared to $\Lambda$CDM. In this work, we present a new estimator of the Lyman-$\alpha$ flux power…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 Mathias Garny , Thomas Konstandin , Laura Sagunski , Sean Tulin

We introduce a new set of large scale, high resolution hydrodynamical simulations of the intergalactic medium: the Sherwood simulation suite. These are performed in volumes 10^3-160^3 h^-3 comoving Mpc^{3}, span almost four orders of…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-07 James S. Bolton , Ewald Puchwein , Debora Sijacki , Martin G. Haehnelt , Tae-Sun Kim , Avery Meiksin , John A. Regan , Matteo Viel

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

The distribution of absorption lines in the spectra of distant quasars, called the Lyman-$\alpha$ (Ly-$\alpha$) forest, is a unique probe of cosmology and the intergalactic medium at high redshifts and small scales. The statistical power of…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-02 Roger de Belsunce , Mikhail M. Ivanov , James M. Sullivan , Kazuyuki Akitsu , Shi-Fan Chen

On large scales, the Lyman-$\alpha$ forest provides insights into the expansion history of the Universe, while on small scales, it imposes strict constraints on the growth history, the nature of dark matter, and the sum of neutrino masses.…

Observations of the Lyman-$\alpha$ (Ly$\alpha$) forest in spectra of distant quasars enable us to probe the matter power spectrum at relatively small scales. With several upcoming surveys, it is expected that there will be a many-fold…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-15 Bhaskar Arya , Tirthankar Roy Choudhury , Aseem Paranjape , Prakash Gaikwad

(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

We implement the hydro-PM (HPM) technique (Gnedin & Hui 1998) in the hydrodynamical simulation code GADGET-II and quantify the differences between this approximate method and full hydrodynamical simulations of the Lyman-alpha forest in a…

Astrophysics · Physics 2009-11-11 Matteo Viel , Martin G. Haehnelt , Volker Springel