Kashaf EmbreenCIIT/FA19-RMT-022/LHRDr. Abdul JawadLHR TP 74402026-05-052021https://repository.cuilahore.edu.pk/123456789/3818In this thesis, we study the inflationary scenario in the realm of k-essence model and swampland conjecture. Taking into account three models of Chaplygin gas, that is, generalized, modified and generalized cosmic Chap- lygin gas models, we discuss the slow roll parameters (²(φ), η(φ)), curvature perturbation (Ps), tensor to scaler ratio (r) and scaler spectral index (ns). In reference to k-essence model, the coupling function as a function of scaler field L(φ) is used. We investigate the swampland conjecture and then find the value of ζ(φ) i.e bound of second conjecture for the above three models by unifying swampland conjecture and k-essence. We plot the inflationary parameters and bound of swampland conjecture r −ns, ζ(φ) − φ, and check their values according to Planck data 2018.enDepartment of MathematicsFA19MathematicsCosmic InflationSwampland ConjecturesDr. Abdul JawadThesis