ABSTRACT
Transformations, conservation laws, and symmetries have played an important role in the development of modern quantum mechanics. This chapter includes translation in space and time, rotation in space and rotation operator, parity operations and space inversion, time reversal operator and its properties for both zero and non-zero spin particles, solved examples, and unsolved exercises. The chapter discusses in detail how the rotation in space leads to important relations between various components of orbital and total angular momenta, which play an important role in formulations of quantum mechanics. Parity conservation and the most striking properties of the parity operator, relevance of time reversal in classical and quantum mechanical descriptions, and the antiunitary and antilinear properties of the time reversal operator are also featured details in the chapter.
