No Arabic abstract
We propose that the Hawking radiation energy and entropy flow rates from a black hole can be viewed as a one-dimensional (1D), non-equilibrium Landauer transport process. Support for this viewpoint comes from previous calculations invoking conformal symmetry in the near-horizon region, which give radiation rates that are identical to those of a single 1D quantum channel connected to a thermal reservoir at the Hawking temperature. The Landauer approach shows in a direct way the particle statistics independence of the energy and entropy fluxes of a black hole radiating into vacuum, as well as one near thermal equilibrium with its environment. As an application of the Landauer approach, we show that Hawking radiation gives a net entropy production that is 50% larger than that obtained assuming standard three-dimensional emission into vacuum.
Following the initial work of Calcagni et al. on the black holes in multi-fractional theories, we focus on the Schwarzschild black hole in multi-fractional theory with q-derivatives. After presenting its Hawking and Hayward temperatures in detail, we verify these results by appealing to the well-known Hamilton-Jacobi and null geodesic methods of the tunnelling approach to Hawking radiation. A special emphasis is placed on the difference between the geometric and fractional frames.
We investigate wave optical imaging of black holes with Hawking radiation. The spatial correlation function of Hawking radiation is expressed in terms of transmission and reflection coefficients for scalar wave modes and evaluated by taking summation over angular qunatum numbers numerically for the Unruh-Hawking state of the Kerr-de Sitter black hole. Then wave optical images of evaporating black hole are obtained by Fourier transformation of the spatial correlation function. For short wavelength, the image of the black hole with the outgoing mode of the Unruh-Hawking state looks like a star with its surface is given by the photon sphere. It is found that interference between incoming modes from the cosmological horizon and reflected modes due to scattering of the black hole can enhance brightness of images in the vicinity of the photon sphere. For long wavelenth, whole field of view becomes bright and emission region of Hawking radiation cannot be identifed.
Stimulated emission by black holes is discussed in light of the analogue gravity program. We first consider initial quantum states containing a definite number of particles, and then we take into account the case where the initial state is a coherent state. The latter case is particularly significant in the case where Hawking radiation is studied in dielectric black holes, and the emission is stimulated by a laser probe. We are particularly interested in the case of the electromagnetic field, for which stimulated radiation is calculated too.
Hawking radiation from Unruhs and Canonical acoustic black hole is considered from viewpoint of anomaly cancellation method developed by Robinson and Wilczek. Thus, the physics near the horizon can be described using an infinite collection of massless two-dimensional scalar fields in the background of a dilaton and the gravitational anomaly is canceled by the flux of a 1 + 1 dimensional blackbody at the Hawking temperature of the space-time. Consequently, by this method, we can get the Hawkings temperature for Canonical and Unruhs acoustic black hole.
We present a solution of Einstein equations with quintessential matter surrounding a $d$-dimensional black hole, whose asymptotic structures are determined by the state of the quintessential matter. We examine the thermodynamics of this black hole and find that the mass of the black hole depends on the equation of state of the quintessence, while the first law is universal. Investigating the Hawking radiation in this black hole background, we observe that the Hawking radiation dominates on the brane in the low-energy regime. For different asymptotic structures caused by the equation of state of the quintessential matter surrounding the black hole, we learn that the influences by the state parameter of the quintessence on Hawking radiation are different.