1 code implementation • 11 Jul 2022 • T. Lucas Makinen, Tom Charnock, Pablo Lemos, Natalia Porqueres, Alan Heavens, Benjamin D. Wandelt
We a) demonstrate the high sensitivity of modular graph structure to the underlying cosmology in the noise-free limit, b) show that graph neural network summaries automatically combine mass and clustering information through comparisons to traditional statistics, c) demonstrate that networks can still extract information when catalogues are subject to noisy survey cuts, and d) illustrate how nonlinear IMNN summaries can be used as asymptotically optimal compressed statistics for Bayesian simulation-based inference.
no code implementations • 13 Nov 2020 • Natalia Porqueres, Alan Heavens, Daniel Mortlock, Guilhem Lavaux
In this case, the density field samples are generated with a power spectrum that deviates from the prior, and the method recovers the true lensing power spectrum.
Cosmology and Nongalactic Astrophysics Instrumentation and Methods for Astrophysics
1 code implementation • 26 Feb 2019 • Florent Leclercq, Wolfgang Enzi, Jens Jasche, Alan Heavens
We propose a new, likelihood-free approach to inferring the primordial matter power spectrum and cosmological parameters from arbitrarily complex forward models of galaxy surveys where all relevant statistics can be determined from numerical simulations, i. e. black-boxes.
Cosmology and Nongalactic Astrophysics Instrumentation and Methods for Astrophysics
2 code implementations • 11 Apr 2017 • Alan Heavens, Yabebal Fantaye, Arrykrishna Mootoovaloo, Hans Eggers, Zafiirah Hosenie, Steve Kroon, Elena Sellentin
In this paper, we present a method for computing the marginal likelihood, also known as the model likelihood or Bayesian evidence, from Markov Chain Monte Carlo (MCMC), or other sampled posterior distributions.
Computation Cosmology and Nongalactic Astrophysics
2 code implementations • 28 May 2015 • Alexander Mead, John Peacock, Catherine Heymans, Shahab Joudaki, Alan Heavens
We are able to fit all feedback models investigated at the 5 per cent level using only two free parameters, and we place limits on the range of these halo parameters for feedback models investigated by the OWLS simulations.
Cosmology and Nongalactic Astrophysics
1 code implementation • 6 Nov 1999 • Alan Heavens, Raul Jimenez, Ofer Lahav
We show that, if the noise in the data is independent of the parameters, we can form $M$ linear combinations of the data which contain as much information about all the parameters as the entire dataset, in the sense that the Fisher information matrices are identical; i. e. the method is lossless.
astro-ph Rings and Algebras Data Analysis, Statistics and Probability