Nadia Khan NergisSP23-RMT-023Dr. Rabia SaleemLHR TP 95662026-03-182024-03-18https://repository.cuilahore.edu.pk/handle/123456789/2932Our goal in this thesis is to examine cosmic warm inflation within the context of mas sive gravity (MG). The late-time cosmic acceleration can be satisfactorily explained by the dRGT gravity, but inflation cannot be supported by it. However, in the framework of General Relativity (GR) and Modified Gravity, the interest in inflation and attempts to use Lagrangians to characterize inflation and dark energy (DE) have recently undergone en hancements and may include poles. We demonstrate how this type of Lagrangian could support inflation within the context of dRGT (de Rham Gabadadze Tolley) gravity theory. We will also compute the fundamental inflationary parameters (slow-roll parameters, spec tral index, e-foldings number, and tensor to scalar ratio). The Planck data’s restrictions on inflationary observables are used to determine the range of the free parameters. The find ings of this study, which concentrate on the power and exponential potentials, appear to be consistent with the Planck 2018 data.enDepartment of MathematicsMathematicsSP23DevelopmentCosmic InflationaryMechanismMassive GravityThesis