caa a22 4500 46906563X CHVBK 20180323132907.0 cr unu---uuuuu 170328e19921201xx s 000 0 eng 10.1007/BF02722856 doi (NATIONALLICENCE)springer-10.1007/BF02722856 Lo C. Department of Physics, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong aut Remarks on squeezed states of a harmonic oscillator in spatially flat Robertson-Walker space-time [Elektronische Daten] [C. Lo] Summary: We have investigated the time evolution of a non-relativistic harmonic oscillator in a spatially flat Robertson-Walker background space-time. It is found that the time evolution operator of the system is a product of a squeeze operator and a rotation operator, and thus the initial cohrent state evolves into a squeezed state at a later time. In other words, the time evolution of the non-relativistic oscillator in a spatially flat Robertson-Walker background spacetime is a <<squeezing>> process. The squeezing effect is induced by the continuous scale dilation in expanding space-time, and depends on the specific model for an expanding universe. For instance, there is no squeezing in the de Sitter model, whereas squeezing does occur in the spatially flat Friedmann model. Società Italiana di Fisica, 1992 PACS 03.65 Quantum theory nationallicence quantum mechanics nationallicence PACS 42.50Dv Nonclassical photon states (including antibunched, squeezed, sub-Poissonian) nationallicence PACS 98.80 Cosmology nationallicence Il Nuovo Cimento B (1971-1996) Società Italiana di Fisica 107/12(1992-12-01), 1451-1454 107:12<1451 1992 107 40764 https://doi.org/10.1007/BF02722856 text/html Onlinezugriff via DOI 1 brief-communication jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02722856 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Lo C. Department of Physics, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong aut NATIONALLICENCE 773 0- Il Nuovo Cimento B (1971-1996) Società Italiana di Fisica 107/12(1992-12-01), 1451-1454 107:12<1451 1992 107 40764 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer