2024/12/15 by Singh, Akanksha, Shaily, Singh, J. K. +1
#Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc)
paper · doi:10.48550/arxiv.2412.12210
In this paper, we construct an isotropic cosmological model in the f(Q, T) theory of gravity in the frame of a flat FLRW spacetime being Q the non-metricity tensor and T the trace of the energy-momentum tensor. The gravity function is taken to be a quadratic equation, f(Q, T)=ζQ2 + γT , where ζ<0 and γ are the arbitrary constants. We constrain the model parameters α and H0 using the recent observational datasets: the Hubble dataset (OHD), the Pantheon dataset of 1048 points, and the joint dataset (OHD + Pantheon ). The universe model transitions from an early deceleration state to an acceleration in late times. This model also provides the ekpyrotic phase of the universe on the redshift z>12.32 . In this model, the Big Bang is described as a collision of branes, and thus, the Big Bang is not the beginning of time. Before the Big Bang, there is an ekpyrotic phase with the equation of state ω>> 1 . In late times, the undeviating Hubble measurements reduce the H0 tension in the reconstructed f(Q, T) function. Additionally, we study various physical parameters of the model. Finally, our model describes a quintessence dark energy model at later times.