297,605 research outputs found
Do peaked solitary water waves indeed exist?
Many models of shallow water waves admit peaked solitary waves. However, it
is an open question whether or not the widely accepted peaked solitary waves
can be derived from the fully nonlinear wave equations. In this paper, a
unified wave model (UWM) based on the symmetry and the fully nonlinear wave
equations is put forward for progressive waves with permanent form in finite
water depth. Different from traditional wave models, the flows described by the
UWM are not necessarily irrotational at crest, so that it is more general. The
unified wave model admits not only the traditional progressive waves with
smooth crest, but also a new kind of solitary waves with peaked crest that
include the famous peaked solitary waves given by the Camassa-Holm equation.
Besides, it is proved that Kelvin's theorem still holds everywhere for the
newly found peaked solitary waves. Thus, the UWM unifies, for the first time,
both of the traditional smooth waves and the peaked solitary waves. In other
words, the peaked solitary waves are consistent with the traditional smooth
ones. So, in the frame of inviscid fluid, the peaked solitary waves are as
acceptable and reasonable as the traditional smooth ones. It is found that the
peaked solitary waves have some unusual and unique characteristics. First of
all, they have a peaked crest with a discontinuous vertical velocity at crest.
Especially, the phase speed of the peaked solitary waves has nothing to do with
wave height. In addition, the kinetic energy of the peaked solitary waves
either increases or almost keeps the same from free surface to bottom. All of
these unusual properties show the novelty of the peaked solitary waves,
although it is still an open question whether or not they are reasonable in
physics if the viscosity of fluid and surface tension are considered.Comment: 53 pages, 13 figures, 7 tables. Accepted by Communications in
Nonlinear Science and Numerical Simulatio
Radiation and energy release in a background field of axion-like dark matter
We find that a fuzzy dark matter background and the mG scale magnetic field
in the galactic center can give rise to a radiation with a very large energy
release. The frequency of the radiation field is the same as the frequency of
the oscillating axion-like background field. We show that there is an energy
transfer between the fuzzy dark matter sector and the electromagnetic sector
because of the presence of the generated radiation field and the galactic
magnetic field. The energy release rate of radiation is found to be very slow
in comparison with the energy of fuzzy dark matter but could be significant
comparing with the energy of galactic magnetic field in the source region.
Using this example, we show that the fuzzy dark matter together with a large
scale magnetic field is possible to give rise to fruitful physics.Comment: 9 pages, no figure, references added, version in PL
Hard Probe of Soft Matter Geometry and Fluctuations from RHIC to LHC
We report results on event-by-event hard probe of soft matter geometry and
fluctuations in heavy ion collisions. Geometric data ( of high
hadrons) from RHIC plus LHC clearly favors jet "monography" model with strong
near-Tc enhancement of jet-medium interaction strength which also implies a
less opaque medium at LHC. We also quantify the jet responses to all harmonic
anisotropy () and their manifestation in hard-soft
azimuthal correlations.Comment: 3 pages, 4 figures, contribution to CIPANP2012 Proceeding
Optimization of Renormalization Group Flow
Renormalization group flow equations for scalar lambda Phi^4 are generated
using three classes of smooth smearing functions. Numerical results for the
critical exponent nu in three dimensions are calculated by means of a truncated
series expansion of the blocked potential. We demonstrate how the convergence
of nu as a function of the order of truncation can be improved through a fine
tuning of the smoothness of the smearing functions.Comment: 23 pages, 7 figure
Dynamic Uplink/Downlink Resource Management in Flexible Duplex-Enabled Wireless Networks
Flexible duplex is proposed to adapt to the channel and traffic asymmetry for
future wireless networks. In this paper, we propose two novel algorithms within
the flexible duplex framework for joint uplink and downlink resource allocation
in multi-cell scenario, named SAFP and RMDI, based on the awareness of
interference coupling among wireless links. Numerical results show significant
performance gain over the baseline system with fixed uplink/downlink resource
configuration, and over the dynamic TDD scheme that independently adapts the
configuration to time-varying traffic volume in each cell. The proposed
algorithms achieve two-fold increase when compared with the baseline scheme,
measured by the worst-case quality of service satisfaction level, under a low
level of traffic asymmetry. The gain is more significant when the traffic is
highly asymmetric, as it achieves three-fold increase.Comment: 7 pages, 7 figures, ICC 2017 Worksho
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