English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

By using the invariant method we find one-parameter squeezed Gaussian statesfor both time-independent and time-dependent oscillators. The squeezingparameter is expressed in terms of energy expectation value fortime-independent case and represents the degree of mixing positive and negativefrequency solutions for time-dependent case. A {\it minimum uncertaintyproposal} is advanced to select uniquely vacuum states at each moment of time.We show that the Gaussian states with minimum uncertainty coincide with thetrue vacuum state for time-independent oscillator and the Bunch-Davies vacuumfor a massive scalar field in a de Sitter spacetime.Comment: 13 Pages, ReVTeX, no figure

One-parameter squeezed Gaussian states of a time-dependent harmonic oscillator and the selection rule for vacuum states