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Full-physics cosmological simulations are powerful tools for studying the formation and evolution of structure in the universe but require extreme computational resources. Here, we train a convolutional neural network to use a cheaper…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-04 Peter Harrington , Mustafa Mustafa , Max Dornfest , Benjamin Horowitz , Zarija Lukić

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

Cosmological hydrodynamic simulations can accurately predict the properties of the intergalactic medium (IGM), but only under the condition of retaining high spatial resolution necessary to resolve density fluctuations in the IGM. This…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-17 Daniele Sorini , José Oñorbe , Zarija Lukić , Joseph F. Hennawi

We explore the use of Deep Learning to infer physical quantities from the observable transmitted flux in the Lyman-alpha forest. We train a Neural Network using redshift z=3 outputs from cosmological hydrodynamic simulations and mock…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-07 Lawrence Huang , Rupert A. C. Croft , Hitesh Arora

The signature left in quasar spectra by the presence of neutral hydrogen in the Universe allows one to constrain the sum of the neutrino masses with improved sensitivity, with respect to laboratory experiments, and may shed a new light on…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-05 Graziano Rossi , Nathalie Palanque-Delabrouille , Arnaud Borde , Matteo Viel , Christophe Yeche , James S. Bolton , James Rich , Jean-Marc Le Goff

In the procedure of constraining the cosmological parameters with the observational Hubble data and the type Ia supernova data, the combination of Masked Autoregressive Flow and Denoising Autoencoder can perform a good result. The above…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-22 Jie-Feng Chen , Yu-Chen Wang , Tingting Zhang , Tong-Jie Zhang

We use the Sherwood-Relics suite of hybrid hydrodynamical and radiative transfer simulations to model the effect of inhomogeneous reionisation on the 1D power spectrum of the \Lya forest transmitted flux at redshifts $4.2\leq z \leq 5$.…

We use the probability distribution function (PDF) of the lya forest flux at z=2-3, measured from high-resolution UVES/VLT data, and hydrodynamical simulations to obtain constraints on cosmological parameters and the thermal state of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 M. Viel , J. S. Bolton , M. G. Haehnelt

We derive and numerically implement an algorithm for estimating the 3D power spectrum of the Lyman-$\alpha$ (Ly-$\alpha$) forest flux fluctuations. The algorithm exploits the unique geometry of Ly-$\alpha$ forest data to efficiently measure…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-10 Andreu Font-Ribera , Patrick McDonald , Anže Slosar

A promising approach to improve climate-model simulations is to replace traditional subgrid parameterizations based on simplified physical models by machine learning algorithms that are data-driven. However, neural networks (NNs) often lead…

Atmospheric and Oceanic Physics · Physics 2021-04-07 Janni Yuval , Paul A. O'Gorman , Chris N. Hill

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

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

Using a suite of hydrodynamical simulations with cold dark matter, baryons, and neutrinos, we present a detailed study of the effect of massive neutrinos on the 1-D and 3-D flux power spectra of the Lyman-$\alpha$ (Ly$\alpha$) forest. The…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-29 Christian Pedersen , Andreu Font-Ribera , Thomas D. Kitching , Patrick McDonald , Simeon Bird , Anže Slosar , Keir K. Rogers , Andrew Pontzen

We use LUQAS, a sample of 27 high resolution high signal-to-noise UVES quasar (QSO) spectra (Kim et al. 2004), and the Croft et al. (2002) sample together with a set of high resolution large box size hydro-dynamical simulations run with the…

Astrophysics · Physics 2009-11-11 Matteo Viel

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

Wood increment is critical information in forestry management. Previous studies used mathematics models to describe complex growing pattern of forest stand, in order to determine the dynamic status of growing forest stand in multiple…

Computational Engineering, Finance, and Science · Computer Science 2014-05-21 Xiaohui Huang , Xing Hu , Weichang Jiang , Zhi Yang , Hao Li

We present a suite of cosmological N-body simulations with cold dark matter and baryons aiming at modeling the low-density regions of the IGM as probed by the Lyman-$\alpha$ forests at high redshift. The simulations are designed to match…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 A. Borde , N. Palanque-Delabrouille , G. Rossi , M. Viel , J. Bolton , Ch. Yèche , J. -M. LeGoff , J. Rich

We explore the use of Deep Learning to infer the temperature of the intergalactic medium from the transmitted flux in the high redshift Lyman-alpha forest. We train Neural Networks on sets of simulated spectra from redshift z=2-3 outputs of…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-06 Runxuan Wang , Rupert A. C. Croft , Patrick Shaw