Slow sound in a duct, effective transonic flows, and analog black holes
نویسندگان
چکیده
منابع مشابه
Model Dependence of Transonic Properties of Accretion Flows Around Black Holes
We analytically study how the behaviour of accretion flows changes when the flow model is varied. We study the transonic properties of the conical flow, a flow of constant height and a flow in vertical equilibrium and show that all these models are basically identical provided the polytropic constant is suitably changed from one model to another. We show that this behaviour is extendible even w...
متن کاملSpectral variability in transonic discs around black holes
Transonic discs with accretion rates relevant to intrinsically bright Galactic X-ray sources (L ≈ 10–10 erg s) exhibit a time dependent cyclic behaviour due to the onset of a thermal instability driven by radiation pressure. In this paper we calculate radiation spectra emitted from thermally-unstable discs to provide detailed theoretical predictions for observationally relevant quantities. The ...
متن کاملHorizon-Penetrating Transonic Accretion Disks around Rotating Black Holes
The stationary hydrodynamic equations for the transonic accretion disks and flows around rotating black holes are presented by using the Kerr-Schild coordinate where there is no coordinate singularity at the event horizon. We use two types of the causal viscosity prescription, and the boundary conditions for the transonic accretion flows are given at the sonic point. For one type of the causal ...
متن کاملNucleosynthesis in Accretion Flows Around Black Holes
Significant nucleosynthesis is possible in the centrifugal pressure-supported dense and hot region of the accretion flows which deviate from Keplerian disks around black holes. We compute composition changes and energy generations due to such nuclear processes. We use a network containing 255 species and follow the changes in composition. Highly viscous, high-accretion-rate flows deviate from a...
متن کاملBlack Holes as Effective Geometries
Gravitational entropy arises in string theory via coarse graining over an underlying space of microstates. In this review we would like to address the question of how the classical black hole geometry itself arises as an effective or approximate description of a pure state, in a closed string theory, which semiclassical observers are unable to distinguish from the “naive” geometry. In cases wit...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Physical Review D
سال: 2015
ISSN: 1550-7998,1550-2368
DOI: 10.1103/physrevd.92.081503