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Paper   IPM / Astronomy / 18310
School of Astronomy
  Title:   Cosmic strings-induced CMB anisotropies in light of weighted morphology
  Author(s): 
1.  A. Afzal
2.  M. Alakhras
3.  M .H. Jalali Kanafi
4.  S. M. S. Movahed
  Status:   Published
  Journal: Monthly Notices of the Royal Astronomical Society
  No.:  4
  Vol.:  541
  Year:  2025
  Pages:   3851-3868
  Supported by:  IPM
  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 nth conditional moments of derivative (cmd-n). This criterion assigns a distinct weight to each excursion set point based on the associated field. We apply the cmd-n 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-n for the weak non-Gaussian regime up to \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 7.2 deg^2 size with a resolution of 0.42 arc-minutes. Our results demonstrate that the minimum detectable value of cosmic string tension is G\mu\gtrsim 1.9\times 10^{-7} when a noise-free map is analyzed with normalized cmd-n. Whereas for the ACT, CMB-S4, and Planck-like experiments at 95.45\% confidence level, the normalized cmd-n can distinguish the CSs network for G\mu\gtrsim2.9 \times 10^{-7}, G\mu\gtrsim 2.4\times 10^{-7} and G\mu\gtrsim 5.8\times 10^{-7}, respectively. The normalized cmd-n exhibits a significantly enhanced capability in detecting CSs relative to the Minkowski Functionals.

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