81,524 research outputs found
Pulsar Velocity with Three-Neutrino Oscillations in Non-adiabatic Processes
We have studied the position dependence of neutrino energy on the
Kusenko-Segr\`{e} mechanism as an explanation of the proper motion of pulsars.
The mechanism is also examined in three-generation mixing of neutrinos and in a
non-adiabatic case. The position dependence of neutrino energy requires the
higher value of magnetic field such as Gauss in order
to explain the observed proper motion of pulsars. It is shown that possible
non-adiabatic processes decrease the neutrino momentum asymmetry, whereas an
excess of electron neutrino flux over other flavor neutrino fluxes increases
the neutrino momentum asymmetry. It is also shown that a general treatment with
all three neutrinos does not modify the result of the two generation treatment
if the standard neutrino mass hierarchy is assumed.Comment: 8 pages, REVTEX, no figure
Impurity scattering and Friedel oscillations in mono-layer black phosphorus
We study the effect of impurity scattering effect in black phosphorurene (BP)
in this work. For single impurity, we calculate impurity induced local density
of states (LDOS) in momentum space numerically based on tight-binding
Hamiltonian. In real space, we calculate LDOS and Friedel oscillation
analytically. LDOS shows strong anisotropy in BP. Many impurities in BP are
investigated using -matrix approximation when the density is low. Midgap
states appear in band gap with peaks in DOS. The peaks of midgap states are
dependent on impurity potential. For finite positive potential, the impurity
tends to bind negative charge carriers and vise versa. The infinite impurity
potential problem is related to chiral symmetry in BP
Tensor coupling effects on spin symmetry in anti-Lambda spectrum of hypernuclei
The effects of -tensor coupling on the spin
symmetry of spectra in -nucleus systems have
been studied with the relativistic mean-field theory. Taking
C+ as an example, it is found that the tensor coupling
enlarges the spin-orbit splittings of by an order of magnitude
although its effects on the wave functions of are negligible.
Similar conclusions has been observed in -nucleus of different
mass regions, including O+, Ca+ and
Pb+. It indicates that the spin symmetry in
anti-lambda-nucleus systems is still good irrespective of the tensor coupling.Comment: 12 pages, 3 figures
Shockley-Ramo theorem and long-range photocurrent response in gapless materials
Scanning photocurrent maps of gapless materials, such as graphene, often
exhibit complex patterns of hot spots positioned far from current-collecting
contacts. We develop a general framework that helps to explain the unusual
features of the observed patterns, such as the directional effect and the
global character of photoresponse. We show that such a response is captured by
a simple Shockley-Ramo-type approach. We examine specific examples and show
that the photoresponse patterns can serve as a powerful tool to extract
information about symmetry breaking, inhomogeneity, chirality, and other local
characteristics of the system.Comment: 7 pgs, 3 fg
Scalable Mining of Common Routes in Mobile Communication Network Traffic Data
A probabilistic method for inferring common routes from mobile communication network traffic data is presented. Besides providing mobility information, valuable in a multitude of application areas, the method has the dual purpose of enabling efficient coarse-graining as well as anonymisation by mapping individual sequences onto common routes. The approach is to represent spatial trajectories by Cell ID sequences that are grouped into routes using locality-sensitive hashing and graph clustering. The method is demonstrated to be scalable, and to accurately group sequences using an evaluation set of GPS tagged data
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