Towards detecting Primordial non-Gaussianity in the CMB using Spherical Convolutional Neural Networks

Fuente: arXiv
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Main Authors: Melsen, Jorik, Flöss, Thomas, Meerburg, P. Daniel
Format: Preprint
Published: 2024
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author Melsen, Jorik
Flöss, Thomas
Meerburg, P. Daniel
author_facet Melsen, Jorik
Flöss, Thomas
Meerburg, P. Daniel
contents This paper explores a novel application of spherical convolutional neural networks (CNNs) to detect primordial non-Gaussianity in the cosmic microwave background (CMB), a key probe of inflationary dynamics. While effective, traditional estimators encounter computational challenges, especially when considering summary statistics beyond the bispectrum. We propose spherical CNNs as an alternative, directly analysing full-sky CMB maps to overcome limitations in previous machine learning (ML) approaches that relied on data summaries. By training on simulated CMB maps with varying amplitudes of non-Gaussianity, our spherical CNN models show promising alignment with optimal error bounds of traditional methods, albeit at lower-resolution maps. While we explore several different architectures, results from DeepSphere CNNs most closely match the Fisher forecast for Gaussian test sets under noisy and masked conditions. Our study suggests that spherical CNNs could complement existing methods of non-Gaussianity detection in future datasets, provided additional training data and parameter tuning are applied. We discuss the potential for CNN-based techniques to scale with larger data volumes, paving the way for applications to future CMB data sets.
format Preprint
id arxiv_https___arxiv_org_abs_2412_12377
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Towards detecting Primordial non-Gaussianity in the CMB using Spherical Convolutional Neural Networks
Melsen, Jorik
Flöss, Thomas
Meerburg, P. Daniel
Cosmology and Nongalactic Astrophysics
This paper explores a novel application of spherical convolutional neural networks (CNNs) to detect primordial non-Gaussianity in the cosmic microwave background (CMB), a key probe of inflationary dynamics. While effective, traditional estimators encounter computational challenges, especially when considering summary statistics beyond the bispectrum. We propose spherical CNNs as an alternative, directly analysing full-sky CMB maps to overcome limitations in previous machine learning (ML) approaches that relied on data summaries. By training on simulated CMB maps with varying amplitudes of non-Gaussianity, our spherical CNN models show promising alignment with optimal error bounds of traditional methods, albeit at lower-resolution maps. While we explore several different architectures, results from DeepSphere CNNs most closely match the Fisher forecast for Gaussian test sets under noisy and masked conditions. Our study suggests that spherical CNNs could complement existing methods of non-Gaussianity detection in future datasets, provided additional training data and parameter tuning are applied. We discuss the potential for CNN-based techniques to scale with larger data volumes, paving the way for applications to future CMB data sets.
title Towards detecting Primordial non-Gaussianity in the CMB using Spherical Convolutional Neural Networks
topic Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2412.12377