7,671 research outputs found
Noncommutative spaces, the quantum of time and the Lorentz symmetry
We introduce three space-times that are discrete in time and compatible with
the Lorentz symmetry. We show that these spaces are no commutative, with
commutation relations similar to the relations of the Snyder and Yang spaces.
Furthermore, using a reparametrized relativistic particle we obtain a
realization of the Snyder type spaces and we construct an action for them.Comment: 8 pages, to appear in PR
Cavitation and bubble collapse in hot asymmetric nuclear matter
The dynamics of embryonic bubbles in overheated, viscous and non-Markovian
nuclear matter is studied. It is shown that the memory and the Fermi surface
distortions significantly affect the hinderance of bubble collapse and
determine a characteristic oscillations of the bubble radius. These
oscillations occur due to the additional elastic force induced by the memory
integral.Comment: Revtex file (10 pages) and 3 figure
Cloud Formation and Water Transport on Mars after Major Outflow Events
The triggering of a robust water cycle on Mars might have been caused by the gigantic flooding events evidenced by outflow channels. We use the Ames Mars General Circulation Model (MGCM) to test this hypothesis, studying how these presumably abrupt eruptions of water might have affected the climate of Mars in the past. We model where the water ultimately went as part of a transient atmospheric water cycle, to answer questions including: (1) Can sudden introductions of large amounts of water on the Martian surface lead to a new equilibrated water cycle? (2) What are the roles of water vapor and water ice clouds to sudden changes in the water cycle on Mars? (3) How are radiative feedbacks involved with this? (4) What is the ultimate fate of the outflow water? (5) Can we tie certain geological features to outflow water redistributed by the atmosphere
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