Speaker
Description
The 21 cm line of neutral hydrogen provides a powerful observational window into the early Universe, particularly during the Dark Ages (redshifts ( z \sim 30\text{--}200 )), before the emergence of the first luminous objects. In this work, presented a theoretical study of the angular power spectrum ( C_\ell ) of 21 cm brightness temperature fluctuations and its dependence on key cosmological parameters.
Described a linear perturbation framework that accounts for density inhomogeneities, peculiar velocities (redshift-space distortions). By modeling the 3D power spectrum of the 21 cm signal and projecting it into angular multipole space, could be investigated the sensitivity of ( C_\ell ) to variations in parameters such as the total matter density ( \Omega_m ), baryon fraction ( \Omega_b ), Hubble constant ( H_0 ), and the fluctuation amplitude ( \sigma_8 ).
Results show that the 21 cm angular power spectrum is sensitive to these parameters, especially at high multipoles where small-scale information is preserved. This highlights the potential of future radio interferometric observations—such as those by the Square Kilometre Array (SKA)—to provide competitive constraints on the cosmological model.
