1,690 research outputs found
Dymanics of Generalized Coherent States
We show that generalized coherent states follow Schr\"{o}dinger dynamics in
time-dependent potentials. The normalized wave-packets follow a classical
evolution without spreading; in turn, the Schr\"{o}dinger potential depends on
the state through the classical trajectory. This feedback mechanism with
continuous dynamical re-adjustement allows the packets to remain coherent
indefinetely.Comment: 8 pages, plain latex, no figure
Non-Newtonian Gravity, Fluctuative Hypothesis and the Sizes of Astrophysical Structures
We show that the characteristic sizes of astrophysical and cosmological
structures, where gravity is the only overall relevant interaction assembling
the system, have a phenomenological relation to the microscopic scales whose
order of magnitude is essentially ruled by the Compton wavelength of the
proton. This result agrees with the absence of screening mechanisms for the
gravitational interaction and could be connected to the presence of Yukawa
correcting terms in the Newtonian potential which introduce typical interaction
lengths. Furthermore, we are able to justify, in a straightforward way, the
Sanders--postulated mass of a vector boson considered in order to obtain the
characteristic sizes of galaxies.Comment: 11 pages. to appear in Mod. Phys. Lett.
Diffusion Processes and Coherent States
It is shown that stochastic processes of diffusion type possess, in all
generality, a structure of uncertainty relations and of coherent and squeezed
states. This fact is used to obtain, via Nelson stochastic formulation of
quantum mechanics, the harmonic-oscillator coherent and squeezed states. The
method allows to derive new minimum uncertainty states in time-dependent
oscillator potentials and for the Caldirola-Kanai model of quantum damped
oscillator.Comment: 11 pages, plain LaTe
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