scholarly journals Cosmological dynamics of spatially flat Einstein-Gauss-Bonnet models in various dimensions: Vacuum case

2016 ◽  
Vol 94 (2) ◽  
Author(s):  
Sergey A. Pavluchenko
Keyword(s):  
Vacuum Case

scholarly journals FLAVOR-CONSERVING OSCILLATIONS OF DIRAC-MAJORANA NEUTRINOS

1998 ◽  
Vol 13 (29) ◽  
pp. 5023-5036 ◽  
Author(s):  
SALVATORE ESPOSITO
Keyword(s):  
Transition Probability ◽  
Normal Medium ◽  
Resonant Enhancement ◽  
Vacuum Case ◽  
Helicity Conservation ◽  
Majorana Neutrinos

We analyze both chirality-changing and chirality-preserving transitions of Dirac–Majorana neutrinos. In vacuum, the first ones are suppressed with respect to the others due to helicity conservation and the interactions with a ("normal") medium practically does not affect the expressions of the probabilities for these transitions, even if the amplitudes of oscillations change slightly. For usual situations involving relativistic neutrinos we find no resonant enhancement for all flavor-conserving transitions. However, for very light neutrinos propagating in superdense media, the pattern of oscillations [Formula: see text] is dramatically altered with respect to the vacuum case, the transition probability practically vanishing. An application of this result is envisaged.

scholarly journals HYDRODYNAMICS OF THE VACUUM

2006 ◽  
Vol 21 (13n14) ◽  
pp. 2877-2903 ◽  
Author(s):  
P. M. STEVENSON
Keyword(s):  
Soliton Solutions ◽  
Empty Space ◽  
Effective Theory ◽  
Pitaevskii Equation ◽  
Hydrodynamic Equations ◽  
Wave Regime ◽  
Hydrodynamic Description ◽  
Normal Medium ◽  
Fluid Medium ◽  
Vacuum Case

Hydrodynamics is the appropriate "effective theory" for describing any fluid medium at sufficiently long length scales. This paper treats the vacuum as such a medium and derives the corresponding hydrodynamic equations. Unlike a normal medium the vacuum has no linear sound-wave regime; disturbances always "propagate" nonlinearly. For an "empty vacuum" the hydrodynamic equations are familiar ones (shallow water-wave equations) and they describe an experimentally observed phenomenon — the spreading of a clump of zero-temperature atoms into empty space. The "Higgs vacuum" case is much stranger; pressure and energy density, and hence time and space, exchange roles. The speed of sound is formally infinite, rather than zero as in the empty vacuum. Higher-derivative corrections to the vacuum hydrodynamic equations are also considered. In the empty-vacuum case the corrections are of quantum origin and the post-hydrodynamic description corresponds to the Gross–Pitaevskii equation. We conjecture the form of the post-hydrodynamic corrections in the Higgs case. In the (1+1)-dimensional case the equations possess remarkable "soliton" solutions and appear to constitute a new exactly integrable system.

The interpretion of the C metric. The vacuum case

1995 ◽  
Vol 27 (4) ◽  
pp. 439-454 ◽  
Author(s):  
F. H. J. Cornish ◽  
W. J. Uttley
Keyword(s):  
Vacuum Case

Testing of the Superconducting Magnet and Cryogenics for the AMS-02 Experiment

2011 ◽  
Vol 21 (3) ◽  
pp. 1868-1871 ◽  
Author(s):  
Peter McIntyre
Keyword(s):  
Thermal Model ◽  
Superconducting Magnet ◽  
Cryogenic System ◽  
Thermal Vacuum ◽  
Test Beam ◽  
Fully Integrated ◽  
Vacuum Case

The superconducting magnet, cryogenics, and detector systems of the AMS experiment was fully integrated and tested in test beam at CERN during 2009. In Spring 2010 the experiment underwent thermal vacuum tests at ESTEC, where it was operated in conditions simulating those that will pertain in orbit. All elements of the superconducting magnet and cryogenics performed as designed, and equilibrium operation was attained at several values of vacuum case temperature. Details of the tests are presented. A thermal model of the overall cryogenic system was calibrated from those measurements. The model was used to predict the cryogenic lifetime of the experiment, as it would be staged on ISS, to be (28 ± 6) months.

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