408 research outputs found
Multiwavelength Observations of MASTER OT 075353.88+174907.6:A Likely Superoutburst of a Long Period Dwarf Nova System
Unexpected late-time temperature increase observed in the two neutron star crust-cooling sources XTE J1701-462 and EXO 0748-676
A "Hyperburst" in the MAXI J0556-332 Neutron Star:Evidence for a New Type of Thermonuclear Explosion
On modulational instability and energy localization in anharmonic lattices at finite energy density
The localization of vibrational energy, induced by the modulational
instability of the Brillouin-zone-boundary mode in a chain of classical
anharmonic oscillators with finite initial energy density, is studied within a
continuum theory. We describe the initial localization stage as a gas of
envelope solitons and explain their merging, eventually leading to a single
localized object containing a macroscopic fraction of the total energy of the
lattice. The initial-energy-density dependences of all characteristic time
scales of the soliton formation and merging are described analytically. Spatial
power spectra are computed and used for the quantitative explanation of the
numerical results.Comment: 12 pages, 7 figure
Primordial black holes in braneworld cosmologies: Accretion after formation
We recently studied the formation and evaporation of primordial black holes
in a simple braneworld cosmology, namely Randall-Sundrum Type II. Here we study
the effect of accretion from the cosmological background onto the black holes
after formation. While it is generally believed that in the standard cosmology
such accretion is of negligible importance, we find that during the high-energy
regime of braneworld cosmology accretion can be the dominant effect and lead to
a mass increase of potentially orders of magnitude. However, unfortunately the
growth is exponentially sensitive to the accretion efficiency, which cannot be
determined accurately. Since accretion becomes unimportant once the high-energy
regime is over, it does not affect any constraints expressed at the time of
black hole evaporation, but it can change the interpretation of those
constraints in terms of early Universe formation rates.Comment: 6 pages RevTeX4 file. Extension to discussion of thermal balance and
grey-body factor
Continued cooling of the accretion-heated neutron star crust in the X-ray transient IGR J17480-2446 located in the globular cluster Terzan 5
Consistent accretion-induced heating of the neutron-star crust in MXB 1659-29 during two different outbursts
Non-perturbative orientifold transitions at the conifold
After orientifold projection, the conifold singularity in hypermultiplet
moduli space of Calabi-Yau compactifications cannot be avoided by geometric
deformations. We study the non-perturbative fate of this singularity in a local
model involving O6-planes and D6-branes wrapping the deformed conifold in Type
IIA string theory. We classify possible A-type orientifolds of the deformed
conifold and find that they cannot all be continued to the small resolution.
When passing through the singularity on the deformed side, the O-plane charge
generally jumps by the class of the vanishing cycle. To decide which classical
configurations are dynamically connected, we construct the quantum moduli space
by lifting the orientifold to M-theory as well as by looking at the
superpotential. We find a rich pattern of smooth and phase transitions
depending on the total sixbrane charge. Non-BPS states from branes wrapped on
non-supersymmetric bolts are responsible for a phase transition. We also
clarify the nature of a Z_2 valued D0-brane charge in the 6-brane background.
Along the way, we obtain a new metric of G_2 holonomy corresponding to an
O6-plane on the three sphere of the deformed conifold.Comment: 76 pages, references adde
Study of the Process e+ e- --> omega pi0 --> pi0 pi0 gamma in c.m. Energy Range 920--1380 MeV at CMD-2
The cross section of the process e+ e- --> omega pi0 --> pi0 pi0 gamma has
been measured in the c.m. energy range 920-1380 MeV with the CMD-2 detector.
Its energy dependence is well described by the interference of the rho(770) and
rho'(1450) mesons decaying to omega pi0. Upper limits for the cross sections of
the direct processes e+ e- --> pi0 pi0 gamma, eta pi0 gamma have been set.Comment: Accepted for publication in PL
Prevalence of dental disorders in an abattoir population of horses in South Africa by oral examination of intact and bisected heads
Dental care is an integral part of equine veterinary practice. The objectives of
this cross sectional study were to describe the prevalence of dental disorders in an
abattoir population of horses, and to compare oral examination of intact and bisected
heads. Heads from 40 horses were examined, 19 males and 21 females, divided into
immature, adults and older horses. Older horses in this abattoir population had a
significantly higher prevalence of infundibular caries (91.7%), diastemata (66.7%)
and fractures (58.3%), whereas dental wear disorders affected all age groups.
Gasterophilus larvae were detected in 20% of the horses. The oral examination
performed on intact heads was adequate for diagnosing gross disorders, but further
examination is needed for reliably diagnosing minor disorders.Abe Bailey Trust, the Department of Companion Animal Clinical Studies, Faculty of Veterinary Science Research Fund, and the South African Veterinary Foundation.http://www.elsevier.com/locate/tvjlhb2016Companion Animal Clinical StudiesProduction Animal Studie
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