1 code implementation • 27 Feb 2024 • Deaglan J. Bartlett, Benjamin D. Wandelt, Matteo Zennaro, Pedro G. Ferreira, Harry Desmond
We then again exploit symbolic regression to explore the space of analytic expressions to fit the residuals between $P(k)$ and the optimised predictions of halofit.
1 code implementation • 27 Nov 2023 • Deaglan J. Bartlett, Lukas Kammerer, Gabriel Kronberger, Harry Desmond, Pedro G. Ferreira, Benjamin D. Wandelt, Bogdan Burlacu, David Alonso, Matteo Zennaro
We obtain an analytic approximation to the linear power spectrum with a root mean squared fractional error of 0. 2% between $k = 9\times10^{-3} - 9 \, h{\rm \, Mpc^{-1}}$ and across a wide range of cosmological parameters, and we provide physical interpretations for various terms in the expression.
no code implementations • 25 Oct 2023 • Tomás Sousa, Deaglan J. Bartlett, Harry Desmond, Pedro G. Ferreira
Inflation is a highly favoured theory for the early Universe.
1 code implementation • 13 Apr 2023 • Deaglan J. Bartlett, Harry Desmond, Pedro G. Ferreira
In this paper we develop methods to incorporate detailed prior information on both functions and their parameters into SR. Our prior on the structure of a function is based on a $n$-gram language model, which is sensitive to the arrangement of operators relative to one another in addition to the frequency of occurrence of each operator.
1 code implementation • 11 Jan 2023 • Harry Desmond, Deaglan J. Bartlett, Pedro G. Ferreira
We apply a new method for learning equations from data -- Exhaustive Symbolic Regression (ESR) -- to late-type galaxy dynamics as encapsulated in the radial acceleration relation (RAR).
6 code implementations • 21 Nov 2022 • Deaglan J. Bartlett, Harry Desmond, Pedro G. Ferreira
To address these issues we introduce Exhaustive Symbolic Regression (ESR), which systematically and efficiently considers all possible equations -- made with a given basis set of operators and up to a specified maximum complexity -- and is therefore guaranteed to find the true optimum (if parameters are perfectly optimised) and a complete function ranking subject to these constraints.
no code implementations • 2 Jul 2020 • Deaglan J. Bartlett, Harry Desmond, Julien Devriendt, Pedro G. Ferreira, Adrianne Slyz
We study the displacements between the centres of galaxies and their supermassive black holes (BHs) in the cosmological hydrodynamical simulation Horizon-AGN, and in a variety of observations from the literature.
Astrophysics of Galaxies Cosmology and Nongalactic Astrophysics
no code implementations • 28 Oct 2016 • David Alonso, Emilio Bellini, Pedro G. Ferreira, Miguel Zumalacarregui
The next generation of surveys will greatly improve our knowledge of cosmological gravity.
Cosmology and Nongalactic Astrophysics General Relativity and Quantum Cosmology High Energy Physics - Theory
3 code implementations • 5 Apr 2016 • Macarena Lagos, Tessa Baker, Pedro G. Ferreira, Johannes Noller
In the case of vector-tensor theories, we first construct the most general quadratic action for perturbations that leads to second-order equations of motion, which propagates two scalar DoFs.
General Relativity and Quantum Cosmology Cosmology and Nongalactic Astrophysics High Energy Physics - Theory
3 code implementations • 10 Oct 2014 • Renée Hlozek, Daniel Grin, David J. E. Marsh, Pedro G. Ferreira
For m < 10^{-32} eV, ULAs are allowed to compose a significant fraction of the dark energy.
Cosmology and Nongalactic Astrophysics High Energy Physics - Experiment High Energy Physics - Phenomenology High Energy Physics - Theory
1 code implementation • 30 Sep 2014 • David Alonso, Philip Bull, Pedro G. Ferreira, Mario G. Santos
For well-behaved foregrounds and instrumental effects we find that foreground subtraction can be successful to a reasonable level on most scales of interest.
Cosmology and Nongalactic Astrophysics
2 code implementations • 25 Mar 2014 • Hans A. Winther, Pedro G. Ferreira
We propose a simple and computationally fast method for performing N-body simulations for a large class of modified gravity theories with a screening mechanism such as chameleons, symmetrons and galileons.
Cosmology and Nongalactic Astrophysics General Relativity and Quantum Cosmology