http://arxiv.org/abs/1911.06378
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, the Simons Observatory, and CMB-S4 experiments. These bounds cannot be saturated by any method.
R. Ciuca and O. Hernández
Mon, 18 Nov 19
48/48
Comments: 7 pages, 1 figure, 1 table
You must be logged in to post a comment.