Cosmological Parameter Estimation with Sequential Linear Simulation-based Inference

Fuente: arXiv
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Main Authors: Mediato-Diaz, Nicolas, Handley, Will
Format: Preprint
Published: 2025
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author Mediato-Diaz, Nicolas
Handley, Will
author_facet Mediato-Diaz, Nicolas
Handley, Will
contents We develop the framework of Linear Simulation-based Inference (LSBI), an application of simulation-based inference where the likelihood is approximated by a Gaussian linear function of its parameters. We obtain analytical expressions for the posterior distributions of hyper-parameters of the linear likelihood in terms of samples drawn from a simulator, for both uniform and conjugate priors. This method is applied sequentially to several toy-models and tested on emulated datasets for the Cosmic Microwave Background temperature power spectrum. We find that convergence is achieved after four or five rounds of $\mathcal{O}(10^4)$ simulations, which is competitive with state-of-the-art neural density estimation methods. Therefore, we demonstrate that it is possible to obtain significant information gain and generate posteriors that agree with the underlying parameters while maintaining explainability and intellectual oversight.
format Preprint
id arxiv_https___arxiv_org_abs_2501_03921
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Cosmological Parameter Estimation with Sequential Linear Simulation-based Inference
Mediato-Diaz, Nicolas
Handley, Will
Instrumentation and Methods for Astrophysics
Cosmology and Nongalactic Astrophysics
Data Analysis, Statistics and Probability
Machine Learning
We develop the framework of Linear Simulation-based Inference (LSBI), an application of simulation-based inference where the likelihood is approximated by a Gaussian linear function of its parameters. We obtain analytical expressions for the posterior distributions of hyper-parameters of the linear likelihood in terms of samples drawn from a simulator, for both uniform and conjugate priors. This method is applied sequentially to several toy-models and tested on emulated datasets for the Cosmic Microwave Background temperature power spectrum. We find that convergence is achieved after four or five rounds of $\mathcal{O}(10^4)$ simulations, which is competitive with state-of-the-art neural density estimation methods. Therefore, we demonstrate that it is possible to obtain significant information gain and generate posteriors that agree with the underlying parameters while maintaining explainability and intellectual oversight.
title Cosmological Parameter Estimation with Sequential Linear Simulation-based Inference
topic Instrumentation and Methods for Astrophysics
Cosmology and Nongalactic Astrophysics
Data Analysis, Statistics and Probability
Machine Learning
url https://arxiv.org/abs/2501.03921