294 research outputs found
On Construction of Recursion Operators From Lax Representation
In this work we develop a general procedure for constructing the recursion
operators fro non-linear integrable equations admitting Lax representation.
Svereal new examples are given. In particular we find the recursion operators
for some KdV-type of integrable equations.Comment: Latex File (AMS format), 23 pages, to be published in Journal of
Mathematical Physic
Mass Distribution and "Mass Gap" of Compact Stellar Remnants in Binary Systems
The highest critical mass of neutron stars (NSs) was reviewed in the context
of equation of state and observationsl results/ It was predicted that the
maximum NS mass (MNS) exists in the range MNS ~ 2.2-2.9 M_Sun. However, recent
observations of gravitationsl waves and other studies had suggested the higher
mass limit of NSs, MNS ~ 3/2 M_Sun. The NS mass up to the value of MNS ~ 2
M_Sun is well understood, and with such a mass value it was meaning ful to
discuss the "mass gap" ("m-gap") between the NS and black hole (BH)
collapsars.The "m-gap" exists in between the highest mass of NS and the lowest
mass of BH collapsars (Mm-gap ~ 2-5 M_Sun). in the mass distribution, the
maximim population of NSs and BHs is located at MNS = 1.4 M_Sun and MBH = 6.7
M_Sun, respectively. However, recent ofservational results predicted filling
the "m-gap" by the compact objects. In this paper, the concept of gravidynamics
was reported to resolve the problem of peak likelihood value of gravitational
mass at Mpeak = 6.7 M_Sun and the "m-gap" (Mm-gap ~ 2-5 M_Sun). This concept
was based on a non-metric scalar-tensor model of gravitational interaction with
localizable field energy. The gravidynamics model shows the total mass (MQ) of
a compact relativistic object filled with matter of quark-gluon plasma of the
radius r* = GMQ/c2 ~ 10 km, consistent with the "m-gap". It was conceptualized
that the total measurable gravitational mass of such an extremely dense object
consists of both matter and field, which is described by scalar-tensor
components. This model is also useful for predicting the collapsars within the
"m-gap".Comment: 25 pages, 4 figures, accepted for publication in Astrophysical
Bulletin, vol.77. arXiv admin note: text overlap with arXiv:1309.6635,
arXiv:1006.2834, arXiv:1909.05804 by other author
Dipole resonances and the nuclear Schiff moment
The nuclear Schiff moment creates a mechanism of transfer of the violation of
parity and time-reversal invariance by weak interaction in nuclei into the
atomic electric dipole moment. We point out an additional contribution to the
Schiff moment generated by the mixing of single-particle states through the
low-lying nuclear dipole resonances. An estimate shows that this contribution
is by order of magnitude comparable to single-particle contributions and can be
enhanced if the low-lying resonance has collective nature.Comment: 11 pages, no figure
Integrable quadratic Hamiltonians on so(4) and so(3,1)
We investigate a special class of quadratic Hamiltonians on so(4) and so(3,1)
and describe Hamiltonians that have additional polynomial integrals. One of the
main results is a new integrable case with an integral of sixth degree.Comment: 16 page
- …