Information Theoretic Bounds on Cosmic String Detection in CMB Maps with Noise

Abstract

We use a convolutional neural network (CNN) to study cosmic string detection in cosmic microwave background (CMB) flat sky maps with Nambu-Goto strings. On noiseless maps we can measure string tensions down to order $10^{-9}$, however when noise is included we are unable to measure string tensions below $10^{-7}$. Motivated by this impasse, we derive an information theoretic bound on the detection of the cosmic string tension $G\mu$ from CMB maps. In particular we bound the information entropy of the posterior distribution of $G\mu$ in terms of the resolution, noise level and total survey area of the CMB map. We evaluate these bounds for the ACT, SPT-3G, Simons Observatory, Cosmic Origins Explorer, and CMB-S4 experiments. These bounds cannot be saturated by any method.

v3: corrected error in table 1 entry for the CORE experiment. This matches the erratum submitted for the version published in MNRAS. 7 pages, 1 figure, 1 table

References in corpus (14)

• The Simons Observatory: Science goals and forecasts
• CMB-S4 Science Case, Reference Design, and Project Plan
• Small-Angle CMB Temperature Anisotropies Induced by Cosmic Strings
• Stochastic gravitational waves from cosmic string loops in scaling
• New CMB constraints for Abelian Higgs cosmic strings
• The 21 cm Signature of Cosmic String Wakes
• Detecting Cosmic Strings in the CMB with the Canny Algorithm
• Constraints on the Nambu-Goto cosmic string contribution to the CMB power spectrum in light of new temperature and polarisation data
• All sky CMB map from cosmic strings integrated Sachs-Wolfe effect
• Type I Abelian Higgs strings: evolution and Cosmic Microwave Background constraints
• A Bayesian Framework for Cosmic String Searches in CMB Maps
• Multi-Scale Pipeline for the Search of String-Induced CMB Anisotropies
• Cosmic String Detection with Tree-Based Machine Learning
• Inferring Cosmic String Tension through the Neural Network Prediction of String Locations in CMB Maps

Cited by in corpus (7)

• Beyond the Standard Models with Cosmic Strings
• The Milky Way bar and bulge revealed by APOGEE DR16 and Gaia EDR3
• Reconstructing Patchy Reionization with Deep Learning
• Extracting the Signal of Cosmic String Wakes from 21-cm Observations
• On self-gravitating kinks in two-dimensional pseudo-riemannian universes
• Planck Limits on Cosmic String Tension Using Machine Learning
• The Global 21 cm Signal of a Network of Cosmic String Wakes