5,207 research outputs found
Accretion physics of AM Herculis binaries, I. Results from one-dimensional stationary radiation hydrodynamics
We have solved the one-dimensional stationary two-fluid hydrodynamic
equations for post-shock flows on accreting magnetic white dwarfs simultaneous
with the fully frequency and angle-dependent radiative transfer for cyclotron
radiation and bremsstrahlung. Magnetic field strengths B = 10 to 100 MG are
considered. At given B, this theory relates the properties of the emission
region to a single physical parameter, the mass flow density (or accretion rate
per unit area). We present the normalized temperature profiles and fit formulae
for the peak electron temperature, the geometrical shock height, and the column
density of the post-shock flow. The results apply to pillbox-shaped emission
regions. With a first-order temperature correction they can also be used for
narrower columns provided they are not too tall.Comment: 10 pages with 10 Postscript figures, accepted for publication in
Astronomy & Astrophysics. The source file contains Table 1a/b in ASCII forma
Anomalies and O-plane charges in orientifolded brane tilings
We investigate orientifold of brane tilings. We clarify how the cancellations
of gauge anomaly and Witten's anomaly are guaranteed by the conservation of the
D5-brane charge. We also discuss the relation between brane tilings and the
dual Calabi-Yau cones realized as the moduli spaces of gauge theories. Two
types of flavor D5-branes in brane tilings and corresponding superpotentials of
fundamental quark fields are proposed, and it is shown that the massless loci
of these quarks in the moduli space correctly reproduce the worldvolume of
flavor D7-branes in the Calabi-Yau cone dual to the fivebrane system.Comment: 46 pages, 19 figure
Large time asymptotics of growth models on space-like paths II: PNG and parallel TASEP
We consider the polynuclear growth (PNG) model in 1+1 dimension with flat
initial condition and no extra constraints. The joint distributions of surface
height at finitely many points at a fixed time moment are given as marginals of
a signed determinantal point process. The long time scaling limit of the
surface height is shown to coincide with the Airy_1 process. This result holds
more generally for the observation points located along any space-like path in
the space-time plane. We also obtain the corresponding results for the discrete
time TASEP (totally asymmetric simple exclusion process) with parallel update.Comment: 39 pages,6 figure
Polynuclear growth model, GOE and random matrix with deterministic source
We present a random matrix interpretation of the distribution functions which
have appeared in the study of the one-dimensional polynuclear growth (PNG)
model with external sources. It is shown that the distribution, GOE, which
is defined as the square of the GOE Tracy-Widom distribution, can be obtained
as the scaled largest eigenvalue distribution of a special case of a random
matrix model with a deterministic source, which have been studied in a
different context previously. Compared to the original interpretation of the
GOE as ``the square of GOE'', ours has an advantage that it can also
describe the transition from the GUE Tracy-Widom distribution to the GOE.
We further demonstrate that our random matrix interpretation can be obtained
naturally by noting the similarity of the topology between a certain
non-colliding Brownian motion model and the multi-layer PNG model with an
external source. This provides us with a multi-matrix model interpretation of
the multi-point height distributions of the PNG model with an external source.Comment: 27pages, 4 figure
Holographic Penta and Hepta Quark State in Confining Gauge Theories
We study a new embedding solutions of D5 brane in an asymptotic
AdS space-time, which is dual to a confining gauge
theory. The D5 brane is wrapped on as in the case of the vertex of
holographic baryon. However, the solution given here is different from the
usual baryon vertex in the point that it couples to -anti-quarks and
quarks on the opposite two points of , the north and south poles,
respectively. The total quark number of this state is preserved as when
minus one is assigned to anti-quark, then it forms a color singlet like the
baryon. However, this includes anti-quarks and quarks, whose number is larger
than that of the baryon. When we set as , we find the so called penta
and hepta-quark states. We study the dynamical properties of these states by
solving the vertex and string configurations for such states. The mass spectra
of these states and the tension of the stretched vertex are estimated, and they
are compared with that of the baryon.Comment: 24 pages, 6 figure
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