Transition probability and preferential gauge

: This paper is concerned with whether or not the preferential gauge can ensure the uniqueness and correctness of results obtained from the standard time-dependent perturbation theory, in which the transition probability is formulated in terms of matrix elements of Hamiltonian. For a dynamical quantum process, the major objective of the existing perturbation theory is to calculate the transition probability between different eigenstates. The theory, which was proposed by Dirac at the very early stage of quantum theory[1] and has been serving as an important part of quantum mechanics in textbooks[2], gives an analytical expression of transition probability in terms of matrix elements of the Hamiltonian representing perturbations. concept