Aryana Haghjoo

Physics Department, McGill University

Unraveling non-standard physics through global 21cm signal

Abstract: The global 21cm signal is a modern tool to study the period between the end of the cosmic dark ages and the epoch of ionization (EoR).

In this talk, we explore the potential of this signal to reveal non-standard physics by means of providing a new path to test fundamental physical theories. The 21cm signal is sensitive to the density and temperature of neutral hydrogen in the early universe and the formation of the first stars and galaxies. Therefore, any deviation from the predictions of the standard cosmological model of this signal could indicate the presence of new physics beyond the standard model.

We will briefly revisit the theoretical basis of the global 21cm signal (Wouthuysen-Field coupling) and the current international efforts to detect it through radio interferometers. Then, we will pave the way to analyze the upcoming data by introducing a special method for parameter estimation of the global 21cm signal. We adopt the Markov Chain Monte Carlo (MCMC) method combined with the Levenberg Marquardt (LM) algorithm to estimate the best-fit physical parameters (e.g., clumping factor, star formation efficiency). We use the Accelerated Reionization Era Simulations (ARES) to generate models for the global 21-cm signal. This method provides comprehensive control over the parameters of the algorithm, allowing to opt for any combination of parameters available within the ARES framework.

The knowledge of these best-fit parameters will help us to constrain future proposed models and set theoretical limits for the precision of upcoming experiments to observe non-standard effects.

یکشنبه 21 خرداد 1402، ساعت 20:00

Sunday 11 June 2023 – 20:00 Tehran Time

https://vc.sharif.edu/ch/cosmology

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