Some phenomenological aspects of low scale quantum gravity

As a resolution of the well-known hierarchy problem,like supersymmetry the model of extra spatialdimension(s) proposed by N.~Arkani-Hamed,S.~Dimopoulos and G.~Dvali(ADD) in 1998, and byL.~Randall and R.~Sundrum(RS) in 1999, have generatedconsiderable enthusiasm among the physics community. In this thesis, we have made a phenomenologicalstudy of both of these models. After a briefintroduction of the ADD model and the RS modelin chapter 1 and chapter 2 and a brief review of theexisting phenomenlogical studies in chapter 3, wehave derived the order $kappa^2$ Feynman rules inthe context of ADD model. In chapter 5, we haveinvestigated theeffect of gravity in the DIS (i.e. the process $e^+ +p rightarrow e^+ X$) and compare our result withthat at HERA to constrain the parameters of the RSmodel. In chapter 6 and chapter 7, we haveinvestigated several phenomenologicalconsequences of the radion (which appears naturallyin the RS model in order to stabilize thesize of the fifth spatial dimension). Chapter 8contains the summary and the conclusion of the thesis.