English

Cosmic Strings-induced CMB anisotropies in light of Weighted Morphology

Cosmology and Nongalactic Astrophysics 2025-08-19 v3 Instrumentation and Methods for Astrophysics High Energy Physics - Phenomenology Computational Physics Methodology

Abstract

Motivated by the morphological measures in assessing the geometrical and topological properties of a generic cosmological stochastic field, we propose an extension of the weighted morphological measures, specifically the nnth conditional moments of derivative (cmd-nn). This criterion assigns a distinct weight to each excursion set point based on the associated field. We apply the cmd-nn on the Cosmic Microwave Background (CMB) to identify the cosmic string networks (CSs) through their unique Gott-Kaiser-Stebbins effect on the temperature anisotropies. We also formulate the perturbative expansion of cmd-nn for the weak non-Gaussian regime up to O(σ03)\mathcal{O}(\sigma_0^3). We propose a comprehensive pipeline designed to analyze the morphological properties of string-induced CMB maps within the flat sky approximation. To evaluate the robustness of our proposed criteria, we employ string-induced high-resolution flat-sky CMB simulated patches of 7.27.2 deg2^2 size with a resolution of 0.420.42 arc-minutes. Our results demonstrate that the minimum detectable value of cosmic string tension is Gμ1.9×107G\mu\gtrsim 1.9\times 10^{-7} when a noise-free map is analyzed with normalized cmd-nn. Whereas for the ACT, CMB-S4, and Planck-like experiments at 95.45\% confidence level, the normalized cmd-nn can distinguish the CSs network for Gμ2.9×107G\mu\gtrsim2.9 \times 10^{-7}, Gμ2.4×107G\mu\gtrsim 2.4\times 10^{-7} and Gμ5.8×107G\mu\gtrsim 5.8\times 10^{-7}, respectively. The normalized cmd-nn exhibits a significantly enhanced capability in detecting CSs relative to the Minkowski Functionals.

Keywords

Cite

@article{arxiv.2503.00758,
  title  = {Cosmic Strings-induced CMB anisotropies in light of Weighted Morphology},
  author = {Adeela Afzal and M. Alakhras and M. H. Jalali Kanafi and S. M. S. Movahed},
  journal= {arXiv preprint arXiv:2503.00758},
  year   = {2025}
}

Comments

20 pages, 10 figures and 3 tables, comments are welcome, V2: added some references, V3: matched to the published version