8,233 research outputs found
Chiral field theory of glueball
A chiral field theory of glueball is presented. By adding a
glueball field to a successful Lagrangian of chiral field theory of
pseudoscalar, vector, and axial-vector mesons, the Lagrangian of this theory is
constructed. The couplings between the pseodoscalar glueball field and mesons
are via U(1) anomaly revealed. Qualitative study of the physical processes of
the glueball of is presented. The theoretical
predictions can be used to identify the glueball.Comment: 29 page
Gamma-ray Burst Afterglow with Continuous Energy Injection: Signature of a Highly-Magnetized Millisecond Pulsar
We investigate the consequences of a continuously injecting central engine on
the gamma-ray burst afterglow emission, focusing more specifically on a
highly-magnetized millisecond pulsar engine. For initial pulsar parameters
within a certain region of the parameter space, the afterglow lightcurves are
predicted to show a distinctive achromatic bump feature, the onset and duration
of which range from minutes to months, depending on the pulsar and the fireball
parameters. The detection of or upper limits on such features would provide
constraints on the burst progenitor and on magnetar-like central engine models.
An achromatic bump such as that in GRB 000301C afterglow may be caused by a
millisecond pulsar with P0=3.4 millisecond and Bp=2.7e14 Gauss.Comment: 5 pages, emulateapj style, to appear in ApJ Letters, updated with the
accepted version, a few corrections are mad
Universality and properties of neutron star type I critical collapses
We study the neutron star axisymmetric critical solution previously found in
the numerical studies of neutron star mergers. Using neutron star-like initial
data and performing similar merger simulations, we demonstrate that the
solution is indeed a semi-attractor on the threshold plane separating the basin
of a neutron star and the basin of a black hole in the solution space of the
Einstein equations. In order to explore the extent of the attraction basin of
the neutron star semiattractor, we construct initial data phase spaces for
these neutron star-like initial data. From these phase spaces, we also observe
several interesting dynamical scenarios where the merged object is supported
from prompt collapse. The properties of the critical index of the solution, in
particular, its dependence on conserved quantities, are then studied. From the
study, it is found that a family of neutron star semi-attractors exist that can
be classified by both their rest masses and ADM masses.Comment: 13 pages, 12 figures, 1 new reference adde
Life Tables of Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae): with a Mathematical Invalidation for Applying the Jackknife Technique to the Net Reproductive Rate
Life table data for the melon fly, Bactrocera cucurbitae (Coquillett), reared on cucumber (Cucumis sativus L.) were collected under laboratory and simulated field conditions. Means and standard errors of life table parameters were estimated for two replicates using the jackknife technique. At 25ºC, the intrinsic rates of increase (_r_) found for the two replicates were 0.1354 and 0.1002 day-1, and the net reproductive rates (_R_~0~) were 206.3 and 66.0 offspring, respectively. When the cucumbers kept under simulated field conditions were covered with leaves, the _r_ and _R_~0~ for the two replicates were 0.0935 and 0.0909 day-1, 17.5 and 11.4 offspring, respectively. However, when similar cucumbers were left uncovered, the _r_ and _R_~0~ for the two replicates were 0.1043 and 0.0904 day-1, and 27.7 and 10.1 offspring, respectively. Our results revealed that considerable variability between replicates in both laboratory and field conditions is possible; this variability should be taken into consideration in data collection and application of life tables. Mathematical analysis has demonstrated that applying the jackknife technique results in unrealistic pseudo-_R_~0~ and overestimation of its variance. We suggest that the jackknife technique should not be used for the estimation of variability of _R_~0~
Vitamin D3 analogues ZK159222 and Zk191784 have anti-inflammatory properties in human adipocytes
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