1 code implementation • 4 Apr 2023 • Yueying Ni, Shy Genel, Daniel Anglés-Alcázar, Francisco Villaescusa-Navarro, Yongseok Jo, Simeon Bird, Tiziana Di Matteo, Rupert Croft, Nianyi Chen, Natalí S. M. de Santi, Matthew Gebhardt, Helen Shao, Shivam Pandey, Lars Hernquist, Romeel Dave
We present CAMELS-ASTRID, the third suite of hydrodynamical simulations in the Cosmology and Astrophysics with MachinE Learning (CAMELS) project, along with new simulation sets that extend the model parameter space based on the previous frameworks of CAMELS-TNG and CAMELS-SIMBA, to provide broader training sets and testing grounds for machine-learning algorithms designed for cosmological studies.
no code implementations • 3 May 2021 • Yueying Ni, Yin Li, Patrick Lachance, Rupert A. C. Croft, Tiziana Di Matteo, Simeon Bird, Yu Feng
In this work, we expand and test the capabilities of our recently developed super-resolution (SR) model to generate high-resolution (HR) realizations of the full phase-space matter distribution, including both displacement and velocity, from computationally cheap low-resolution (LR) cosmological N-body simulations.
no code implementations • 13 Oct 2020 • Yin Li, Yueying Ni, Rupert A. C. Croft, Tiziana Di Matteo, Simeon Bird, Yu Feng
Cosmological simulations of galaxy formation are limited by finite computational resources.
2 code implementations • 12 Jun 2020 • Leah Fauber, Ming-Feng Ho, Simeon Bird, Christian R. Shelton, Roman Garnett, Ishita Korde
Our technique is an extension of an earlier Gaussian process method for detecting damped Lyman-alpha absorbers (DLAs) in quasar spectra with known redshifts.
Astrophysics of Galaxies Instrumentation and Methods for Astrophysics
1 code implementation • 28 Apr 2020 • M. A. Fernandez, Simeon Bird, Yanou Cui
We show that the largest effect of the cosmic string is an overdensity in the filament distribution around the string wake.
Cosmology and Nongalactic Astrophysics General Relativity and Quantum Cosmology High Energy Physics - Phenomenology High Energy Physics - Theory
1 code implementation • 24 Mar 2020 • Ming-Feng Ho, Simeon Bird, Roman Garnett
We present a revised version of our automated technique using Gaussian processes (GPs) to detect Damped Lyman-$\alpha$ absorbers (DLAs) along quasar (QSO) sightlines.
Cosmology and Nongalactic Astrophysics Astrophysics of Galaxies Data Analysis, Statistics and Probability
no code implementations • 11 Dec 2018 • Keir K. Rogers, Hiranya V. Peiris, Andrew Pontzen, Simeon Bird, Licia Verde, Andreu Font-Ribera
Starting with a Latin hypercube sampling (other schemes with good space-filling properties can be used), we iteratively augment the training set with extra simulations at new parameter positions which balance the need to reduce interpolation error while focussing on regions of high likelihood.
Cosmology and Nongalactic Astrophysics
no code implementations • 6 Dec 2017 • Ian G. McCarthy, Simeon Bird, Joop Schaye, Joachim Harnois-Deraps, Andreea S. Font, Ludovic van Waerbeke
Recent studies have presented evidence for tension between the constraints on Omega_m and sigma_8 from the cosmic microwave background (CMB) and measurements of large-scale structure (LSS).
Cosmology and Nongalactic Astrophysics
4 code implementations • 14 May 2016 • Roman Garnett, Shirley Ho, Simeon Bird, Jeff Schneider
We develop an automated technique for detecting damped Lyman-$\alpha$ absorbers (DLAs) along spectroscopic lines of sight to quasi-stellar objects (QSOs or quasars).
Cosmology and Nongalactic Astrophysics Data Analysis, Statistics and Probability
no code implementations • 8 Mar 2016 • Ian G. McCarthy, Joop Schaye, Simeon Bird, Amandine M. C. Le Brun
The evolution of the large-scale distribution of matter is sensitive to a variety of fundamental parameters that characterise the dark matter, dark energy, and other aspects of our cosmological framework.
Cosmology and Nongalactic Astrophysics Astrophysics of Galaxies
no code implementations • 6 May 2014 • Mark Vogelsberger, Shy Genel, Volker Springel, Paul Torrey, Debora Sijacki, Dandan Xu, Gregory F. Snyder, Simeon Bird, Dylan Nelson, Lars Hernquist
Previous simulations of the growth of cosmic structures have broadly reproduced the 'cosmic web' of galaxies that we see in the Universe, but failed to create a mixed population of elliptical and spiral galaxies due to numerical inaccuracies and incomplete physical models.
Cosmology and Nongalactic Astrophysics
no code implementations • 20 Sep 2011 • Simeon Bird, Matteo Viel, Martin G. Haehnelt
We extend the widely used HALOFIT approximation to account for the effect of massive neutrinos on the power spectrum.
Cosmology and Nongalactic Astrophysics