5,186 research outputs found

    Accretion physics of AM Herculis binaries, I. Results from one-dimensional stationary radiation hydrodynamics

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    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

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    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

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    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, GOE2^2 and random matrix with deterministic source

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    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, GOE2^2, 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 GOE2^2 as ``the square of GOE'', ours has an advantage that it can also describe the transition from the GUE Tracy-Widom distribution to the GOE2^2. 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

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    We study a new embedding solutions of D5 brane in an asymptotic AdS5Ă—S5{}_5\times S^5 space-time, which is dual to a confining SU(Nc)SU(N_c) gauge theory. The D5 brane is wrapped on S5S^5 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 kk-anti-quarks and Nc+kN_c+k quarks on the opposite two points of S5S^5, the north and south poles, respectively. The total quark number of this state is preserved as NcN_c 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 Nc=3N_c=3, 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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