Aneesa MajeedCIIT/FA19-RMT-115/LHRDr. Abdul JawadLHR TP 73832026-04-232021https://repository.cuilahore.edu.pk/123456789/3692We explore the swampland conjectures of quintessence and tachyon scalar field models in f(T ) and Einstein gravities, respectively. In f(T ) gravity, we consider cold and warm (by assuming generalized dissipative coefficient) inflationary scenario and develop constraints on de-Sitter con- jectures through Bekenstein entropy relation. In usual inflation, the de- Sitter conjecture constraint becomes constant (in terms of models constant parameters) which can be easily analyzed for its validity (i.e., |V 0| V ≤ O(1)). However, in warm inflation, we analyze the de-Sitter conjecture constraint through T 0V TV 0 , i.e., if T 0V TV 0 < 1 then |V 0| V ≤ O(1) and hence we can obtain required result. For evaluating this condition, we choose three well-known potentials such as monomial chaotic, hilltop and generalized exponential. It is observed that the condition T 0V TV 0 < 1 satisfied for all three potentials in both regimes of dissipative coefficient for specific choice of constants. Sim- ilarly, we also obtain satisfactory results of de-Sitter conjecture for tachyon and polytropic (with quintessence scalar field) in general relativity.enDepartment of MathematicsFA19Mathematicspolytropicgeneralized exponentialswampland conjecturesDr. Abdul JawadThesis