. This is an invitation to enjoy watching how unbounded subnormality, a rather recent development, gets involved in solving the commutation relation of the quantum harmonic oscillator. 1991 Mathematic...
The authors present a concise biography of professor Franciszek Raszeja on the sixty years of his death. Special attention is given to his scientific and organizational achievements, particularly in r...
. In a recent paper [5] the creation operator of the quantum harmonic oscillator (its counterpart, the annihilation one as well) is characterized through its (spatial) tranlational invariance property...
. It has been known that positive definiteness does not guarantee for a bisequence to be a complex moment one. However, it turns out that positive definite extendibility does (Theorems 1 and 22), and ...