1,938 research outputs found
The geodesic flow on nilmanifolds
In this paper we study the geodesic flow on nilmanifolds equipped with a
left-invariant metric. We write the underlying definitions and find general
formulas for the Poisson involution. As an example we develop the Heisenberg
Lie group equipped with its canonical metric. We prove that a family of first
integrals giving the complete integrability can be read off at the Lie algebra
of the isometry group. We also explain the complete integrability on compact
quotients and for any invariant metric.Comment: 24 page
Can quantum regression theorem be reconciled with quantum fluctuation dissipation theorem ?
In the attempt to derive the regression theorem from the fluctuation
dissipation theorem several authors claim the violation of the former theorem
in the quantum case. Here we pose the question: does it exists a quantum
fluctuation dissipation theorem (QFDT) in its conventional interpretation? It
is shown that the relation usually called as the QFDT is the condition of
detailed macroscopic energetic balance. Following this interpretation the
existing conflict between the two theorems in the quantum case is removed.Comment: 13 pages, 3rd Int. Conf. on Unsolved Problems on Noise (will be
published in Proceedings
Large mixing angle solution to the solar neutrino problem and random matter density perturbations
There are reasons to believe that mechanisms exist in the solar interior
which lead to random density perturbations in the resonant region of the Large
Mixing Angle solution to the solar neutrino problem. We find that, in the
presence of these density perturbations, the best fit point in the
(sin^2(2\theta), Delta_m^2) parameter space moves to smaller values, compared
with the values obtained for the standard LMA solution. Combining solar data
with KamLAND results, we find a new compatibility region, which we call
VERY-LOW LMA, where sin^2(2\theta) ~ 0.6 and Delta_m^2~2e-5 eV^2, for random
density fluctuations of order 5% < \xi< 8%. We argue that such values of
density fluctuations are still allowed by helioseismological observations at
small scales of order 10 - 1000 km deep inside the solar core.Comment: References and discussion added, with some small numerical
corrections implemente
Networks, commuting and spatial structures: An introduction
JTLU vol. 2, no. 3, (2010) pp 1-4This article introduces vol. 2, no. 3 issue of Journal of Transport and Land Use
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