Investigating the Squeezed Limit of Primordial Non-Gaussianity: New Constraints from CMB Anisotropies [EN]

Events Calendar

 Time:  Friday, December 6, 2024, 12:00 am
 Title:  Investigating the Squeezed Limit of Primordial Non-Gaussianity: New Constraints from CMB Anisotropies [EN]
 Speaker:  Ayodeji ibitoye (NAOC)
 Location:  Physics Building E225

ABSTRACT

The Primordial non-Gaussianity provides fundamental insights into the early Universe and constitutes a crucial area of research in contemporary cosmology. Recently, we extended the cosmological analysis presented in Ibitoye2024 beyond the intergalactic medium (IGM) to investigate the primordial non-Gaussianity parameter (f^0_NL) in the squeezed limit, using the auto- and cross-power spectra of the ISW-tSZ joint on very large scales. We determine the primordial non-Gaussianity to an upper limit value at the 68% confidence level (CL). Furthermore, we further extended the theoretical framework to incorporate the standard energy injection-induced C^yT_\ell distortion anisotropies into the ISW\textendash tSZ cross-power spectrum, to which we obtained an amplitude of f_inj = 0.50 ± 0.21 at the 68% CL. Therefore, in my talk, I plan to discuss our previous attempt to understand the large-scale structure using the thermal Sunyaev-Zeldovich (tSZ) effect and our ongoing effort to investigate the Squeezed Limit of Primordial Non-Gaussianity from CMB Anisotropies.


BIO

I am currently an ANSO fellow (postdoctoral scholar) at the National Astronomical Observatories, Chinese Academy of Sciences, Beijing. Prior to this, I earned a PhD in Cosmology from the University of KwaZulu Natal, South Africa in May, 2021. I earned an MSc (graduated with Distinction) in Theoretical Physics from University of Ibadan, Nigeria, and a BSc (graduated with a First Class) in Physics from Obafemi Awolowo University, Nigeria. My research interest focuses on the cosmological exploitation of different large-scale structure observables and also on 21cm cosmology to gain a better insight into the formation and evolution of cosmic structure in the Universe.


Host: Pablo Renard