105,256 research outputs found
Heisenberg equation for a nonrelativistic particle on a hypersurface: from the centripetal force to a curvature induced force
In classical mechanics, a nonrelativistic particle constrained on an
curved hypersurface embedded in flat space experiences the centripetal
force only. In quantum mechanics, the situation is totally different for the
presence of the geometric potential. We demonstrate that the motion of the
quantum particle is "driven" by not only the the centripetal force, but also a
curvature induced force proportional to the Laplacian of the mean curvature,
which is fundamental in the interface physics, causing curvature driven
interface evolution.Comment: 4 page
Distributed Flow Scheduling in an Unknown Environment
Flow scheduling tends to be one of the oldest and most stubborn problems in
networking. It becomes more crucial in the next generation network, due to fast
changing link states and tremendous cost to explore the global structure. In
such situation, distributed algorithms often dominate. In this paper, we design
a distributed virtual game to solve the flow scheduling problem and then
generalize it to situations of unknown environment, where online learning
schemes are utilized. In the virtual game, we use incentives to stimulate
selfish users to reach a Nash Equilibrium Point which is valid based on the
analysis of the `Price of Anarchy'. In the unknown-environment generalization,
our ultimate goal is the minimization of cost in the long run. In order to
achieve balance between exploration of routing cost and exploitation based on
limited information, we model this problem based on Multi-armed Bandit Scenario
and combined newly proposed DSEE with the virtual game design. Armed with these
powerful tools, we find a totally distributed algorithm to ensure the
logarithmic growing of regret with time, which is optimum in classic
Multi-armed Bandit Problem. Theoretical proof and simulation results both
affirm this claim. To our knowledge, this is the first research to combine
multi-armed bandit with distributed flow scheduling.Comment: 10 pages, 3 figures, conferenc
The centripetal force law and the equation of motion for a particle on a curved hypersurface
It is pointed out that the current form of extrinsic equation of motion for a
particle constrained to remain on a hypersurface is in fact a half-finished
version for it is established without regard to the fact that the particle can
never depart from the geodesics on the surface. Once the fact be taken into
consideration, the equation takes that same form as that for centripetal force
law, provided that the symbols are re-interpreted so that the law is applicable
for higher dimensions. The controversial issue of constructing operator forms
of these equations is addressed, and our studies show the quantization of
constrained system based on the extrinsic equation of motion is favorable.Comment: 5 pages, major revisio
General covariant geometric momentum, gauge potential and a Dirac fermion on a two-dimensional sphere
For a particle that is constrained on an ()-dimensional ()
curved surface, the Cartesian components of its momentum in -dimensional
flat space is believed to offer a proper form of momentum for the particle on
the surface, which is called the geometric momentum as it depends on the mean
curvature. Once the momentum is made general covariance, the spin connection
part can be interpreted as a gauge potential. The present study consists in two
parts, the first is a discussion of the general framework for the general
covariant geometric momentum. The second is devoted to a study of a Dirac
fermion on a two-dimensional sphere and we show that there is the generalized
total angular momentum whose three cartesian components form the
algebra, obtained before by consideration of dynamics of the particle, and we
demonstrate that there is no curvature-induced geometric potential for the
fermion.Comment: 8 pages, no figure. Presentation improve
Charmed Baryon Weak Decays with SU(3) Flavor Symmetry
We study the semileptonic and non-leptonic charmed baryon decays with
flavor symmetry, where the charmed baryons can be , , , or . With denoted as the baryon
octet (decuplet), we find that the
decays are forbidden, while the ,
, and decays are the only existing Cabibbo-allowed modes
for , , and , respectively. We predict the rarely studied
decays, such as and . For the observation, the doubly and triply charmed baryon decays of
, ,
, and are the favored Cabibbo-allowed decays,
which are accessible to the BESIII and LHCb experiments.Comment: 29 pages, no figure, a typo in the table correcte
A note on modular forms and generalized anomaly cancellation formulas
By studying modular invariance properties of some characteristic forms, we
prove some new anomaly cancellation formulas which generalize the Han-Zhang and
Han-Liu-Zhang anomaly cancellation formula
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