Search Results for author: Pedro G. Ferreira

Found 12 papers, 9 papers with code

syren-halofit: A fast, interpretable, high-precision formula for the $Λ$CDM nonlinear matter power spectrum

1 code implementation27 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.

regression Symbolic Regression

A precise symbolic emulator of the linear matter power spectrum

1 code implementation27 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.

Symbolic Regression

Priors for symbolic regression

1 code implementation13 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.

Language Modelling Model Selection +2

On the functional form of the radial acceleration relation

1 code implementation11 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).

regression Relation +2

Exhaustive Symbolic Regression

6 code implementations21 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.

regression Symbolic Regression

Spatially offset black holes in the Horizon-AGN simulation and comparison to observations

no code implementations2 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

The Observational Future of Cosmological Scalar-Tensor Theories

no code implementations28 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

A general theory of linear cosmological perturbations: scalar-tensor and vector-tensor theories

3 code implementations5 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

A search for ultra-light axions using precision cosmological data

3 code implementations10 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

Blind foreground subtraction for intensity mapping experiments

1 code implementation30 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

A Fast Route to Non-Linear Clustering Statistics in Modified Gravity Theories

2 code implementations25 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

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