Research Projects

The late-time accelerating Universe, originating from supernovae observations, has expanded the scope of cosmological research, particularly in understanding dark energy properties. Einstein's General Relativity (GR) has limitations in addressing this issue, leading to the need for modification. Two approaches are proposed: adding extra matter fields to the energy-momentum tensor to explain the cosmic speed up issue, or modifying the geometrical aspect of the Einstein-Hilbert action to create accelerating models without exotic fluids. The focus is on parametrization of geometrical parameters, such as the Hubble parameter, deceleration parameter, jerk and snap parameter, to distinguish between different dark energy models. The H₀ tension issue, which affects the range of values suggested by different cosmological observations, can be addressed by reducing the H₀ tension. Theoretically, constraints cosmological parameters based on teleparallel gravity and its extension. The main focus is to develop functional forms of f(T) and adjust free parameters to result in an accelerating model at late times. To make the models robust, additional terms like Gauss-Bonnet term, scalar field, and trace of energy momentum tensor may be included. This approach introduces a dynamical system by making variables dimensionless, allowing critical properties to be determined without knowing the exact solution of the system of equations.