Issue
EPL
Volume 82, Number 6, June 2008
Article Number 60001
Number of page(s) 5
Section General
DOI http://dx.doi.org/10.1209/0295-5075/82/60001
Published online 27 May 2008
EPL, 82 (2008) 60001
DOI: 10.1209/0295-5075/82/60001

Fermion tunneling from dynamical horizons

R. Di Criscienzo1 and L. Vanzo2

1  Department of Physics-University of Toronto - 60 St. George Street, Toronto, Ontario, M5S 1A7, Canada
2  Dipartimento di Fisica-Università di Trento and INFN, Gruppo Collegato di Trento - Via Sommarive 14, 38100 Povo (Trento) Italia, EU

vanzo@science.unitn.it

received 7 March 2008; accepted in final form 24 April 2008; published June 2008
published online 27 May 2008

Abstract
The instability against emission of fermionic particles by the trapping horizon of an evolving black hole is analyzed and confirmed using the Hamilton-Jacobi tunneling method. This method automatically selects one special expression for the surface gravity of a changing horizon. The results also apply to point masses embedded in an expanding universe. As a bonus of the tunneling method, we gain the insight that the surface gravity still defines a temperature parameter as long as the evolution is sufficiently slow that the black-hole pass through a sequence of quasi-equilibrium states, and that black holes should be semi-classically unstable even in a hypothetical world without bosonic fields.

PACS
04.70.-s - Physics of black holes.
04.70.Bw - Classical black holes.
04.70.Dy - Quantum aspects of black holes, evaporation, thermodynamics.

© EPLA 2008