Adam D Helfer 2001 Class. Quantum Grav. 18 5413 doi:10.1088/0264-9381/18/24/307
Adam D Helfer
Show affiliationsA simple ordinary differential equation is derived governing the redshifts of wavefronts propagating through a non-stationary spherically symmetric space–time. Approach to an event horizon corresponds to approach to a fixed point; in general, the phase portrait of the equation illuminates the qualitative features of the geometry. In particular, the asymptotics of the redshift as the horizon is approached, a critical ingredient of Hawking's prediction of radiation from black holes, are easily brought out. This asymptotic behaviour has elements in common with the universal behaviour near phase transitions in statistical physics. The validity of the Unruh vacuum for the Hawking process can be understood in terms of this universality. The concept of surface gravity is extended to non-stationary spherically symmetric black holes. Finally, it is shown that in the non-stationary case, Hawking's predicted flux of radiation from a black hole would be modified.
04.70.Bw Classical black holes
Issue 24 (21 December 2001)
Received 21 July 2001, in final form 16 October 2001
Published 5 December 2001
Adam D Helfer 2001 Class. Quantum Grav. 18 5413
G Jin et al 1993 J. Phys. D: Appl. Phys. 26 2096
D. Marsden et al. 2001 ApJ 550 397
Robert L. Hurt and Mary Barsony 1996 ApJ 460 L45
C. Done et al. 2000 ApJ 536 213
Cara E. Rakowski et al. 2007 ApJ 655 885
J. L. Sanz et al. 2001 ApJ 552 484
Mukund Rangamani 2009 Class. Quantum Grav. 26 224003
Alessandra Telleschi et al. 2005 ApJ 622 653
V E Antonov et al 2004 J. Phys.: Condens. Matter 16 8387