Absorption and emission spectra of an higher-dimensional Reissner–Nordström black hole

Abstract

The absorption and emission problems of the brane-localized and bulk scalars are examined when the spacetime is a (4+n)-dimensional Reissner-Nordström black hole. Making use of an appropriate analytic continuation, we compute the absorption and emission spectra in the full range of particle's energy. For the case of the brane-localized scalar the presence of the nonzero inner horizon parameter r − generally enhances the absorptivity and suppresses the emission rate compared to the case of the Schwarzschild phase. The low-energy absorption cross section exactly equals to 4πr 2 + , two-dimensional horizon area. The effect of the extra dimensions generally suppresses the absorptivity and enhances the emission rate, which results in the disappearance of the oscillatory pattern in the total absorption cross section when n is large. For the case of the bulk scalar the effect of r − on the spectra is similar to that in the case of the brane-localized scalar. The low-energy absorption cross section equals to the area of the horizon hypersurface. In the presence of the extra dimensions the total absorption cross section tends to be inclined with a positive slope.It turns out that the ratio of the missing energy over the visible one decreases with increase of r − . *

Hawking radiation of the brane-localized graviton from a (4 + n )-dimensional black hole

“…The numerical result of Ref. [5] also supports the argument made by EHM if the number of the extra dimensions is not too large.…”

“…Putting ǫ = 0, we checked our numerical calculation reproduces the absorption and emission spectra of the brane-localized scalar calculated in Ref. [3,5].…”

“…In Ref. [5,6,11] the function R is computed numerically from the near-horizon solution (15) by increasing the convergence region via the analytic continuation. Then Eq.…”

Exact results for evaporating black holes in curvature-squared Lovelock gravity: Gauss-Bonnet greybody factors

“…In the limit of zero black hole angular momentum, the Kerr metric reduces to the Schwarzschild one, and the induced background on the brane assumes the form given in Eq. (9). Using the following factorized ansatz for the propagating field:…”

“…the greybody factors, must be accurately computed. To date, the greybody factors have been obtained for D-dimensional Schwarzschild [5,6,7] (for a detailed review, see [8]), Reissner-Nordstrom [9], Kerr [10,11,12,13] and Schwarzschild-de-Sitter [14] black holes, for various types of emitted fields.…”