Observational constraints on two cosmological models of $f(Q)$ theory

TL;DR

This paper investigates two specific $f(Q)$ gravity models using observational data and statistical methods, comparing their cosmological implications to the standard $bc$CDM model, and finds they fit current data well with accelerating universe behavior.

Contribution

It introduces and tests two novel $f(Q)$ models with a specific EoS parametrization, providing observational constraints and comparison to $bc$CDM.

Findings

Both models fit observational data well.

The models support an accelerating universe.

Parameter values are consistent with current cosmological observations.

Abstract

In the past few years, $f(Q)$ theories have drawn a lot of research attention in replacing Einstein's theory of gravity successfully. The current study examines the novel cosmological possibilities emerging from two specific classes of $f(Q)$ models using the parametrization form of the equation of state (EoS) parameter as $\omega \left( z\right) =-\frac{1}{1+3\beta \left( 1+z\right) ^{3}}$, which displays quintessence behavior with the evolution of the Universe. We do statistical analyses using the Markov chain Monte Carlo (MCMC) method and background datasets like Type Ia Supernovae (SNe Ia) luminosities and direct Hubble datasets (from cosmic clocks), and Baryon Acoustic Oscillations (BAO) datasets. This lets us compare these new ideas about the Universe to the $\Lambda $CDM model in a number of different possible ways. We have come to the conclusion that, at the current level of accuracy, the values of their specific parameters are the best fits for our $f(Q)$ models. To conclude the accelerating behavior of the Universe, we further study the evolution of energy density, pressure, and deceleration parameter for these $f(Q)$ models.