Next Article in Journal
Information, Deformed қ-Wehrl Entropies and Semiclassical Delocalization
Previous Article in Journal
Viscoelastic Effects on the Entropy Production in Oscillatory Flow between Parallel Plates with Convective Cooling
 
 
Article

The Connection Between Entropy and the Absorption Spectra of Schwarzschild Black Holes for Light and Massless Scalar Fields

1
Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, AP 70-264, Distrito Federal 04510, Mexico
2
GEPI, Observatoire de Paris, 5 Place Jules Janssen, 92195 Meudon, France
3
CCADET, Universidad Nacional Autonoma de Mexico, Distrito Federal 04510, Mexico
4
School of Physics and Astronomy, University of Southampton, Highfield, Southampton, SO17 1BJ, UK
*
Author to whom correspondence should be addressed.
Entropy 2009, 11(1), 17-31; https://doi.org/10.3390/e11010017
Received: 11 June 2008 / Accepted: 11 January 2009 / Published: 23 January 2009
We present heuristic arguments suggesting that if EM waves with wavelengths somewhat larger than the Schwarzschild radius of a black hole were fully absorbed by it, the second law of thermodynamics would be violated, under the Bekenstein interpretation of the area of a black hole as a measure of its entropy. Thus, entropy considerations make the well known fact that large wavelengths are only marginally absorbed by black holes, a natural consequence of thermodynamics. We also study numerically the ingoing radial propagation of a scalar field wave in a Schwarzschild metric, relaxing the standard assumption which leads to the eikonal equation, that the wave has zero spatial extent. We find that if these waves have wavelengths larger that the Schwarzschild radius, they are very substantially reflected, fully to numerical accuracy. Interestingly, this critical wavelength approximately coincides with the one derived from entropy considerations of the EM field, and is consistent with well known limit results of scattering in the Schwarzschild metric. The propagation speed is also calculated and seen to differ from the value c, for wavelengths larger than Rs, in the vicinity of Rs. As in all classical wave phenomena, whenever the wavelength is larger or comparable to the physical size of elements in the system, in this case changes in the metric, the zero extent ’particle’ description fails, and the wave nature becomes apparent.
Keywords: Physics of black holes; Classical black holes; Quantum aspects of black holes; evaporation; thermodynamics Physics of black holes; Classical black holes; Quantum aspects of black holes; evaporation; thermodynamics
MDPI and ACS Style

Mendoza, S.; Hernandez, X.; Rendón, P.L.; Lopez-Monsalvo, C.S.; Velasco-Segura, R. The Connection Between Entropy and the Absorption Spectra of Schwarzschild Black Holes for Light and Massless Scalar Fields. Entropy 2009, 11, 17-31. https://doi.org/10.3390/e11010017

AMA Style

Mendoza S, Hernandez X, Rendón PL, Lopez-Monsalvo CS, Velasco-Segura R. The Connection Between Entropy and the Absorption Spectra of Schwarzschild Black Holes for Light and Massless Scalar Fields. Entropy. 2009; 11(1):17-31. https://doi.org/10.3390/e11010017

Chicago/Turabian Style

Mendoza, Sergio, Xavier Hernandez, Pablo L. Rendón, C. S. Lopez-Monsalvo, and Roberto Velasco-Segura. 2009. "The Connection Between Entropy and the Absorption Spectra of Schwarzschild Black Holes for Light and Massless Scalar Fields" Entropy 11, no. 1: 17-31. https://doi.org/10.3390/e11010017

Find Other Styles

Article Access Map by Country/Region

1
Only visits after 24 November 2015 are recorded.
Back to TopTop