Name: Archana Sangwan
Affiliation: Indian Institute of Technology Bombay
Conference ID : ASI2022_465
Title : Constraining the dark energy-dark matter interaction model using low-redshift observations
Authors : Archana Sangwan (Self), Joseph P Johnson, and S. Shankaranarayanan
Abstract Type: Poster
Abstract Category : General Relativity and Cosmology
Abstract : Various observations have shown that dark energy accounts for nearly two-thirds of the energy density of the Universe. The simplest model to explain the nature of dark energy is the cosmological constant ($\Lambda$CDM) model. Although Planck observations support using $\Lambda$CDM model as the base cosmological model, there exist some inconsistencies in parameter estimates when compared with independent observations, most importantly in the $H_0$ estimates. The Planck collaboration reports $H_0 = 67.5^{+0.5}_{-0.5}$ $km~s^{-1}~Mpc^{-1}$, whereas the SH0ES collaboration in 2019, reported $H_0=74.3^{+1.42}_{-1.42}$ $km~s^{-1}~Mpc^{-1}$. This $4\sigma$ discrepancy in $H_0$ estimates, called the Hubble tension, points towards a new physics that deviates from the standard $\Lambda$CDM model and to resolve this various methods have been proposed. In this work, a quintessence scalar field with an inverse power potential (V($\phi$)$\sim$ $\phi^{-n}$) is assumed as a description of dark energy and we focus on an interacting dark energy dark matter model where the interacting term is taken to be linear in the field ($\Phi$). We study in detail the evolution of the model and provide constraints on the model parameters using low redshift cosmological observations of Type Ia Supernovae (SN), baryon acoustic oscillations (BAO), direct measurements of Hubble parameter (Hz) and high redshift HII galaxy measurements (HIIG). We find that the model agrees with the existing values of the cosmological parameters, $\Omega_m$ and $w_0$. The analysis shows that the observations prefer a negative value of coupling constant and give the best fit value of $H_0= 69.79^{+0.29}_{-0.52}$ $km~s^{-1} ~Mpc^{-1}$ and thereby can be used to alleviate the $H_0$ tension between Planck measurements and the observations considered.