29,654 research outputs found
A mathematical form of force-free magnetosphere equation around Kerr black holes and its application to Meissner effect
Based on the Lagrangian of the steady axisymmetric force-free magnetosphere
(FFM) equation around Kerr black holes(KBHs), we find that the FFM equation can
be rewritten in a new form as , where . By coordinate
transformation, the form of the above equation can be given by . Based on the form, we prove finally that the
Meissner effect is not possessed by a KBH-FFM with the condition where
and , here is the component of the vector potential ,
is the angular velocity of magnetic fields and
corresponds to twice the poloidal electric current
Consistency of Perfect Fluidity and Jet Quenching in semi-Quark-Gluon Monopole Plasmas
We utilize a new framework, CUJET3.0, to deduce the energy and temperature
dependence of jet transport parameter, , from a
combined analysis of available data on nuclear modification factor and
azimuthal asymmetries from RHIC/BNL and LHC/CERN on high energy nuclear
collisions. Extending a previous perturbative-QCD based jet energy loss model
(known as CUJET2.0) with (2+1)D viscous hydrodynamic bulk evolution, this new
framework includes three novel features of nonperturbative physics origin: (1)
the Polyakov loop suppression of color-electric scattering (aka "semi-QGP" of
Pisarski et al) and (2) the enhancement of jet scattering due to emergent
magnetic monopoles near (aka "magnetic scenario" of Liao and Shuryak) and
(3) thermodynamic properties constrained by lattice QCD data. CUJET3.0 reduces
to v2.0 at high temperatures MeV, but greatly enhances near
the QCD deconfinement transition temperature range. This enhancement accounts
well for the observed elliptic harmonics of jets with GeV.
Extrapolating our data-constrained down to thermal energy scales, GeV, we find for the first time a remarkable consistency between high
energy jet quenching and bulk perfect fluidity with near .Comment: 6 pages, 4 figures; v2: major text revisions, title and abstract
modified, typos corrected, references adde
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
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