4,416 research outputs found
Local virial relation and velocity anisotropy for collisionless self-gravitating systems
The collisionless quasi-equilibrium state realized after the cold collapse of
self-gravitating systems has two remarkable characters. One of them is the
linear temperature-mass (TM) relation, which yields a characteristic
non-Gaussian velocity distribution. Another is the local virial (LV) relation,
the virial relation which holds even locally in collisionless systems through
phase mixing such as cold-collapse. A family of polytropes are examined from a
view point of these two characters. The LV relation imposes a strong constraint
on these models: only polytropes with index with a flat boundary
condition at the center are compatible with the numerical results, except for
the outer region. Using the analytic solutions based on the static and
spherical Jeans equation, we show that this incompatibility in the outer region
implies the important effect of anisotropy of velocity dispersion. Furthermore,
the velocity anisotropy is essential in explaining various numerical results
under the condition of the local virial relation.Comment: 8 pages, 5 figures, Proceedings of CN-Kyoto International Workshop on
Complexity and Nonextensivity; added a reference for section
Thermodynamic black di-rings
Previously the five dimensional -rotating black rings have been
superposed in a concentric way by some solitonic methods, and regular systems
of two -rotating black rings were constructed by the authors and then
Evslin and Krishnan (we called these solutions "black di-rings"). In this place
we show some characteristics of the solutions of five dimensional black
di-rings, especially in thermodynamic equilibrium. After the summary of the
di-ring expressions and their physical quantities, first we comment on the
equivalence of the two different solution sets of the black di-rings. Then the
existence of thermodynamic black di-rings is shown, in which both isothermality
and isorotation between the inner black ring and the outer black ring are
realized. We also give detailed analysis of peculiar properties of the
thermodynamic black di-ring including discussion about a certain kind of
thermodynamic stability (instability) of the system.Comment: 26 pages,10 figures; references added, typos corredte
A comparison of airborne and ground-based radar observations with rain gages during the CaPE experiment
The vicinity of KSC, where the primary ground truth site of the Tropical Rainfall Measuring Mission (TRMM) program is located, was the focal point of the Convection and Precipitation/Electrification (CaPE) experiment in Jul. and Aug. 1991. In addition to several specialized radars, local coverage was provided by the C-band (5 cm) radar at Patrick AFB. Point measurements of rain rate were provided by tipping bucket rain gage networks. Besides these ground-based activities, airborne radar measurements with X- and Ka-band nadir-looking radars on board an aircraft were also recorded. A unique combination data set of airborne radar observations with ground-based observations was obtained in the summer convective rain regime of central Florida. We present a comparison of these data intending a preliminary validation. A convective rain event was observed simultaneously by all three instrument types on the evening of 27 Jul. 1991. The high resolution aircraft radar was flown over convective cells with tops exceeding 10 km and observed reflectivities of 40 to 50 dBZ at 4 to 5 km altitude, while the low resolution surface radar observed 35 to 55 dBZ echoes and a rain gage indicated maximum surface rain rates exceeding 100 mm/hr. The height profile of reflectivity measured with the airborne radar show an attenuation of 6.5 dB/km (two way) for X-band, corresponding to a rainfall rate of 95 mm/hr
Naked Singularity Explosion
It is known that the gravitational collapse of a dust ball results in naked
singularity formation from an initial density profile which is physically
reasonable. In this paper, we show that explosive radiation is emitted during
the formation process of the naked singularity.Comment: 6 pages, 3 figures, Accepted for Publication in Phys. Rev. D as a
Rapid Communicatio
New Axisymmetric Stationary Solutions of Five-dimensional Vacuum Einstein Equations with Asymptotic Flatness
New axisymmetric stationary solutions of the vacuum Einstein equations in
five-dimensional asymptotically flat spacetimes are obtained by using solitonic
solution-generating techniques. The new solutions are shown to be equivalent to
the four-dimensional multi-solitonic solutions derived from particular class of
four-dimensional Weyl solutions and to include different black rings from those
obtained by Emparan and Reall.Comment: 6 pages, 3 figures;typos corrected, presentations improved,
references added;accepted versio
Rotating Black Holes on Kaluza-Klein Bubbles
Using the solitonic solution generating techniques, we generate a new exact
solution which describes a pair of rotating black holes on a Kaluza-Klein
bubble as a vacuum solution in the five-dimensional Kaluza-Klein theory. We
also investigate the properties of this solution. Two black holes with topology
S^3 are rotating along the same direction and the bubble plays a role in
holding two black holes. In static case, it coincides with the solution found
by Elvang and Horowitz.Comment: 16 pages, 1 figure, minor correctio
General Connectivity Distribution Functions for Growing Networks with Preferential Attachment of Fractional Power
We study the general connectivity distribution functions for growing networks
with preferential attachment of fractional power, ,
using the Simon's method. We first show that the heart of the previously known
methods of the rate equations for the connectivity distribution functions is
nothing but the Simon's method for word problem. Secondly, we show that the
case of fractional the -transformation of the rate equation
provides a fractional differential equation of new type, which coincides with
that for PA with linear power, when . We show that to solve such a
fractional differential equation we need define a transidental function
that we call {\it upsilon function}. Most of all
previously known results are obtained consistently in the frame work of a
unified theory.Comment: 10 page
Classical no-cloning theorem under Liouville dynamics by non-Csisz\'ar f-divergence
The Csisz\'ar f-divergence, which is a class of information distances, is
known to offer a useful tool for analysing the classical counterpart of the
cloning operations that are quantum mechanically impossible for the factorized
and marginality classical probability distributions under Liouville dynamics.
We show that a class of information distances that does not belong to this
divergence class also allows for the formulation of a classical analogue of the
quantum no-cloning theorem. We address a family of nonlinear Liouville-like
equations, and generic distances, to obtain constraints on the corresponding
functional forms, associated with the formulation of classical analogue of the
no-cloning principle.Comment: 6 pages, revised, published versio
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