An overview is given of the use of symmetry considerations for aperiodic crystals. Superspace groups were introduced in the seventies for the description of incommensurate modulated phases with one modulation vector. Later, these groups were also used for quasi-periodic crystals of arbitrary rank. Further extensions use time reversal and time translation operations on magnetic and electrodynami...

Three possibilities for the origin of CP violation are discussed: (1) the Standard Model in which all CP violation is due to one parameter in the CKM matrix, (2) the superweak model in which all CP violation is due to new physics and (3) the Standard Model plus new physics. A major goal of B physics is to distinguish these possibilities. CP violation implies time reversal violation (TRV) but di...

recently, time reversal (tr) method, due to its high functionality in heterogeneous media has been widely employed in microwave imaging (mi) applications. one of the applications turning into a great interest is through-wall microwave imaging (twmi). in this paper, tr method is applied to detect and localize a target obscured by a brick wall using a numerically generated data. regarding this, i...