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We demonstrate that the lyman alpha forest flux power spectrum of ``randomised'' QSO absorption spectra is comparable in shape and amplitude to the flux power spectrum of the original observed spectra. In the randomised spectra a random…

Astrophysics · Physics 2009-11-10 M. Viel , M. G. Haehnelt , R. F. Carswell , T. -S. Kim

This paper investigates probability density functions (PDFs) that are continuous everywhere, nearly uniform around the mode of distribution, and adaptable to a variety of distribution shapes ranging from bell-shaped to rectangular. From the…

Machine Learning · Computer Science 2022-04-01 Osamu Fujita

The thermal state of the intergalactic medium (IGM) contains vital information about the epoch of reionization, one of the most transformative yet poorly understood periods in the young universe. This thermal state is encoded in the…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-20 Molly Wolfson , Joseph F. Hennawi , Frederick B. Davies , Jose Oñorbe , Hector Hiss , Zarija Lukić

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

We present the first simulation of the signature of baryonic acoustic oscillations (BAO) in Lyman alpha forest data containing 180,000 mock quasar sight-lines. We use eight large dark-matter only simulations onto which we paint the Lyman…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-09 Anže Slosar , Shirley Ho , Martin White , Thibaut Louis

We consider the distributed detection problem of a temporally correlated random radio source signal using a wireless sensor network capable of measuring the energy of the received signals. It is well-known that optimal tests in the…

Signal Processing · Electrical Eng. & Systems 2023-12-20 Juan Augusto Maya , Leonardo Rey Vega , Andrea M. Tonello

Current analyses of the Lyman-alpha forest assume that the primordial power spectrum of density perturbations obeys a simple power law, a strong theoretical assumption which should be tested. Employing a large suite of numerical simulations…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-24 Simeon Bird

We demonstrate a method for reconstructing the weak lensing potential from the Lyman-$\alpha$ forest data. We derive an optimal estimator for the lensing potential on the sky based on the correlation between pixels in real space. This…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-21 R. Benton Metcalf , Nicolas Tessore , Rupert A. C. Croft

Inhomogeneous reionization enhances the 1D Lyman-$\alpha$ forest power spectrum on large scales at redshifts $z\geq4$. This is due to coherent fluctuations in the ionized hydrogen fraction that arise from large-scale variations in the…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-29 Margherita Molaro , Vid Iršič , James S. Bolton , Maggie Lieu , Laura C. Keating , Ewald Puchwein , Martin G. Haehnelt , Matteo Viel

On large scales a nonlinear transformation of matter density field can be viewed as a biased tracer of the density field itself. A nonlinear transformation also modifies the redshift space distortions in the same limit, giving rise to a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Uros Seljak

Photon counts statistics have recently been proven to provide a sensitive observable for characterizing gamma-ray source populations and for measuring the composition of the gamma-ray sky. In this work, we generalize the use of the standard…

High Energy Astrophysical Phenomena · Physics 2017-02-22 H. -S. Zechlin , A. Cuoco , F. Donato , N. Fornengo , M. Regis

Deep learning (DL) has been shown to outperform traditional, human-defined summary statistics of the Ly{\alpha} forest in constraining key astrophysical and cosmological parameters owing to its ability to tap into the realm of non-Gaussian…

Instrumentation and Methods for Astrophysics · Physics 2025-10-24 Parth Nayak , Michael Walther , Daniel Gruen

The probability distribution function (PDF) of the mass surface density is an essential characteristic of the structure of molecular clouds or the interstellar medium in general. Observations of the PDF of molecular clouds indicate a…

Astrophysics of Galaxies · Physics 2015-06-18 Joerg Fischera

The Lyman-$\alpha$ forest offers a unique avenue for studying the distribution of matter in the high redshift universe and extracting precise constraints on the nature of dark matter, neutrino masses, and other $\Lambda$CDM extensions.…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-29 Laura Cabayol-Garcia , Jonás Chaves-Montero , Andreu Font-Ribera , Christian Pedersen

Lattice QCD offers the possibility of computing parton distributions from first principles, although not in the usual $\overline{MS}$ factorization scheme. We study in this paper the evolution of non-singlet parton distribution functions…

High Energy Physics - Lattice · Physics 2023-11-01 H. Dutrieux , J. Karpie , C. Monahan , K. Orginos , S. Zafeiropoulos

We use the ellipsoidal collapse approximation to investigate the nonlinear redshift space evolution of the density field with primordial non-Gaussianity of the local f_{nl}-type. We utilize the joint distribution of eigenvalues of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Tsz Yan Lam , Vincent Desjacques , Ravi K. Sheth

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

Parton distribution function (PDF) at small $x$ in a fast-moving proton is investigated within an upgraded parton model that includes parton splitting with branching cascades and parton fusion. In the region of moderately small $x$, we…

High Energy Physics - Phenomenology · Physics 2026-02-27 M. L. Nekrasov

In this article, we construct semiparametrically efficient estimators of linear functionals of a probability measure in the presence of side information using an easy empirical likelihood approach. We use estimated constraint functions and…

Methodology · Statistics 2023-03-01 Shan Wang , Hanxiang Peng

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