6,503 research outputs found
Large branes in AdS and their field theory dual
Recently it was suggested that a graviton in with a large
momentum along the sphere can blow up into a spherical D-brane in . In
this paper we show that the same graviton can also blow up into a spherical
D-brane in with exactly the same quantum numbers (angular momentum and
energy). These branes are BPS, preserving 16 of the 32 supersymmetries. We show
that there is a BPS {\it classical} solution for SYM on with
exactly the same quantum numbers. The solution has non-vanishing Higgs
expectation values and hence is dual to the large brane in AdS.Comment: 20 pages, 6 figures, minor change
A Ray-Tracing Model of the Vela Pulsar
In the relativistic plasma surrounding a pulsar, a subluminal ordinary-mode
electromagnetic wave will propagate along a magnetic field line. After some
distance, it can break free of the field line and escape the magnetosphere to
reach an observer. We describe a simple model of pulsar radio emission based on
this scenario and find that applying this model to the case of the Vela pulsar
reproduces qualitative characteristics of the observed Vela pulse profile.Comment: 23 pages, 9 figures, accepted for publication in Ap
The Effects of Industry on Cross-Border and Domestic IPO Underpricing
Increasing numbers of foreign firms are holding cross-border IPOs in attempts to raise capital in markets outside of their home nation. Within the United States cross-border IPOs consistently experience greater amounts of underpricing than domestic IPOs. This paper examines the effects of SIC industry classifications on cross-border and domestic IPO underpricing from 2004-2010. Analysis demonstrates that in various industries, SIC classification has a significant impact upon underpricing in comparison to other industries. While in other industries, significance is solely exhibited through the differing impacts of domestic and cross-border IPOs, within the industry itself, upon underpricing. The most significant industry effect is seen in high-technology industries which display a significant impact on underpricing on both the inter-industry and intra-industry level
A High Stellar Obliquity in the WASP-7 Exoplanetary System
We measure a tilt of 86+-6 deg between the sky projections of the rotation
axis of the WASP-7 star, and the orbital axis of its close-in giant planet.
This measurement is based on observations of the Rossiter-McLaughlin (RM)
effect with the Planet Finder Spectrograph on the Magellan II telescope. The
result conforms with the previously noted pattern among hot-Jupiter hosts,
namely, that the hosts lacking thick convective envelopes have high
obliquities. Because the planet's trajectory crosses a wide range of stellar
latitudes, observations of the RM effect can in principle reveal the stellar
differential rotation profile; however, with the present data the signal of
differential rotation could not be detected. The host star is found to exhibit
radial-velocity noise (``stellar jitter') with an amplitude of ~30m/s over a
timescale of days.Comment: ApJ accepted, 9 pages, 9 figure
Spin-Orbit Alignment of the TrES-4 Transiting Planetary System and Possible Additional Radial Velocity Variation
We report new radial velocities of the TrES-4 transiting planetary system,
including observations of a full transit, with the High Dispersion Spectrograph
of the Subaru 8.2m telescope. Modeling of the Rossiter-McLaughlin effect
indicates that TrES-4b has closely aligned orbital and stellar spin axes, with
. The close spin-orbit alignment angle
of TrES-4b seems to argue against a migration history involving planet-planet
scattering or Kozai cycles, although there are two nearby faint stars that
could be binary companion candidates. Comparison of our out-of-transit data
from 4 different runs suggest that the star exhibits radial velocity
variability of 20 ms^-1 in excess of a single Keplerian orbit. Although
the cause of the excess radial velocity variability is unknown, we discuss
various possibilities including systematic measurement errors, starspots or
other intrinsic motions, and additional companions besides the transiting
planet.Comment: 10 pages, 3 figures, 3 tables, PASJ in pres
Vortex state in double transition superconductors
Novel vortex phase and nature of double transition field are investigated by
two-component Ginzburg-Landau theory in a situation where fourfold-twofold
symmetric superconducting double transition occurs. The deformation from 60
degree triangular vortex lattice and a possibility of the vortex sheet
structure are discussed. In the presence of the gradient coupling, the
transition changes to a crossover at finite fields. These characters are
important to identify the multiple superconducting phase in PrOs_4_Sb_12.Comment: 4 pages, 4 figures, to appear in Phys. Rev. Let
Aerodynamic characteristics of general aviation at high angle of attack with the propeller slipstream
The aerodynamic characteristics of the FA-300 business aircraft at high angle of attack with the propeller stream are described. The FA-300 offers two types, FA-300-700 for 340 HP, and -710 for 450 Hp of the engine. The effects of the propeller slipstream on the high angle of the attack are discussed
Origin of critical-temperature enhancement of an iron-based high-T_c superconductor, LaFeAsO_{1-x}F_{x} : NMR study under high pressure
Nuclear magnetic resonance (NMR) measurements of an iron (Fe)-based
superconductor LaFeAsO_{1-x}F_x (x = 0.08 and 0.14) were performed at ambient
pressure and under pressure. The relaxation rate 1/T_1 for the overdoped
samples (x = 0.14) shows T-linear behavior just above T_c, and pressure
application enhances 1/T_1T similar to the behavior of T_c. This implies that
1/T_1T = constant originates from the Korringa relation, and an increase in the
density of states at the Fermi energy D(E_F) leads to the enhancement of T_c.
In the underdoped samples (x = 0.08), 1/T_1T measured at ambient pressure also
shows T-independent behavior in a wide temperature range above T_c. However, it
shows Curie-Weiss-like T dependence at 3.0 GPa accompanied by a small increase
in T_c, suggesting that predominant antiferromagnetic fluctuation suppresses
development of superconductivity or remarkable enhancement of T_c. The
qualitatively different features between underdoped and overdoped samples are
systematically explained by a band calculation with hole and electron pockets
Measurements of Stellar Inclinations for Kepler Planet Candidates II: Candidate Spin-Orbit Misalignments in Single and Multiple-Transiting Systems
We present a test for spin-orbit alignment for the host stars of 25 candidate
planetary systems detected by the {\it Kepler} spacecraft. The inclination
angle of each star's rotation axis was estimated from its rotation period,
rotational line broadening, and radius. The rotation periods were determined
using the {\it Kepler} photometric time series. The rotational line broadening
was determined from high-resolution optical spectra with Subaru/HDS. Those same
spectra were used to determine the star's photospheric parameters (effective
temperature, surface gravity, metallicity) which were then interpreted with
stellar-evolutionary models to determine stellar radii. We combine the new
sample with the 7 stars from our previous work on this subject, finding that
the stars show a statistical tendency to have inclinations near 90, in
alignment with the planetary orbits. Possible spin-orbit misalignments are seen
in several systems, including three multiple-planet systems (KOI-304, 988,
2261). Ideally these systems should be scrutinized with complementary
techniques---such as the Rossiter-McLaughlin effect, starspot-crossing
anomalies or asteroseismology---but the measurements will be difficult owing to
the relatively faint apparent magnitudes and small transit signals in these
systems.Comment: 11 pages, 9 figures, accepted for publication in Ap
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