Analysing Hubble Tension and Gravitational Waves for f(Q,T) Gravity Theories

In this work, we examine viable models of f(Q,T) gravity theories against observational data with the aim to constrain the parameter space of these models. We have analyzed four different models of f(Q,T) gravity and tested them against against late-time background probes: Cosmic Chronometer (CC), Baryon Acoustic Oscillations (DESI BAO), Pantheon+ and Gravitational wave(GWTC-3) data. We put stringent constraints on the f(Q,T) gravity models, f(Q,T)=αQ+βT, f(Q,T)=αQn+βT, f(Q,T)=−αQ−βT2 and f(Q,T)=αQ−2T2 along with other late-time cosmological parameters such as deceleration parameter (q0), equation of state parameter (w0), sound horizon distance (rd) and demonstrate their alignment with the ΛCDM model and the observational data. We show that these models have the capability to alleviate the Hubble tension in late time universe, by predicting the present value of the Hubble parameter close to 74 km/s/Mpc. f(Q,T) gravity theory introduces alterations in the background evolution and imposes a friction term in the propagation of gravitational waves, this phenomenon has also been examined. We have shown their agreement with the Gravitational Wave (GW) luminosity distance with the Electromagnetic (EM) counter part GWTC-3 data from Advanced LIGO and Advanced VIRGO across different observing runs capturing coalescence of Binary Neutron Stars (BNS), mergers of Binary Black Holes (BBHs), and Neutron Star-Black Hole (NSBH) binaries with EM counterparts.