*Valeri P. Frolov and Andrei Zelnikov*

- Published in print:
- 2011
- Published Online:
- January 2012
- ISBN:
- 9780199692293
- eISBN:
- 9780191731860
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199692293.003.0009
- Subject:
- Physics, Particle Physics / Astrophysics / Cosmology

This Chapter contains brief review of the theory of classical and quantum fields propagating in the black hole geometry. It includes such subjects as quasinormal modes and ringing radiation, ...
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This Chapter contains brief review of the theory of classical and quantum fields propagating in the black hole geometry. It includes such subjects as quasinormal modes and ringing radiation, separation of variables in the Kerr spacetime and hidden symmetries, Hawking effect and quantum evaporation of black holes, quantum fields in the Rindler frame and the Unruh effect. We formulate and discuss four laws of the black hole thermodynamics. At the end of the Chapter we briefly discuss higher dimension generalizations.Less

This Chapter contains brief review of the theory of classical and quantum fields propagating in the black hole geometry. It includes such subjects as quasinormal modes and ringing radiation, separation of variables in the Kerr spacetime and hidden symmetries, Hawking effect and quantum evaporation of black holes, quantum fields in the Rindler frame and the Unruh effect. We formulate and discuss four laws of the black hole thermodynamics. At the end of the Chapter we briefly discuss higher dimension generalizations.

*Laura Ruetsche*

- Published in print:
- 2011
- Published Online:
- September 2011
- ISBN:
- 9780199535408
- eISBN:
- 9780191728525
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199535408.003.0009
- Subject:
- Philosophy, Philosophy of Science

This chapter develops a case for attributing quantum field theory a particle ontology. When the space of physical states of the theory resides in a Fock space, the observables constituting a particle ...
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This chapter develops a case for attributing quantum field theory a particle ontology. When the space of physical states of the theory resides in a Fock space, the observables constituting a particle notion circumscribed by that Fock space are fundamental in the sense that they form a complete set, so that every state of the theory can be understood in terms of values assigned those observables. The Unruh effect, in which an observer accelerating uniformly through Minkowski spacetime in its vacuum (i.e. no-particle) state observes a thermal distribution of particles, is often presented as a challenge to particle interpretations. Arguing that the standard form of the challenge is miscast, the chapter recasts it in a stronger form: unitarily inequivalent Fock space representations circumscribe incommensurable particle notions, so if physical states reside in multiple, unitarily inequivalent Fock space representations, no single particle notion can be fundamental.Less

This chapter develops a case for attributing quantum field theory a particle ontology. When the space of physical states of the theory resides in a Fock space, the observables constituting a particle notion circumscribed by that Fock space are fundamental in the sense that they form a complete set, so that every state of the theory can be understood in terms of values assigned those observables. The Unruh effect, in which an observer accelerating uniformly through Minkowski spacetime in its vacuum (i.e. no-particle) state observes a thermal distribution of particles, is often presented as a challenge to particle interpretations. Arguing that the standard form of the challenge is miscast, the chapter recasts it in a stronger form: unitarily inequivalent Fock space representations circumscribe incommensurable particle notions, so if physical states reside in multiple, unitarily inequivalent Fock space representations, no single particle notion can be fundamental.

*Laura Ruetsche*

- Published in print:
- 2011
- Published Online:
- September 2011
- ISBN:
- 9780199535408
- eISBN:
- 9780191728525
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199535408.003.0010
- Subject:
- Philosophy, Philosophy of Science

This chapter considers, and finds wanting, several responses to the challenge Chapter 9 announces to interpretations which equip quantum field theory with a particle ontology. One response appeals to ...
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This chapter considers, and finds wanting, several responses to the challenge Chapter 9 announces to interpretations which equip quantum field theory with a particle ontology. One response appeals to the Hadamard condition, a condition states of the quantum field must satisfy to admit an ascription of stress-energy, and so fall within the ambit of semi-classical quantum gravity. The chapter charges that this response constrains physical possibility more stringently than suits creative physics, which makes explanatory and developmental use of states the response brands as unphysical. The charge, that rigid interpretive principles hamstring active physics, is further illustrated by means of coherent states, central to quantum optics and the modeling of certain scattering experiments, but proscribed by apparently reasonable rigid principles of interpretation.Less

This chapter considers, and finds wanting, several responses to the challenge Chapter 9 announces to interpretations which equip quantum field theory with a particle ontology. One response appeals to the Hadamard condition, a condition states of the quantum field must satisfy to admit an ascription of stress-energy, and so fall within the ambit of semi-classical quantum gravity. The chapter charges that this response constrains physical possibility more stringently than suits creative physics, which makes explanatory and developmental use of states the response brands as unphysical. The charge, that rigid interpretive principles hamstring active physics, is further illustrated by means of coherent states, central to quantum optics and the modeling of certain scattering experiments, but proscribed by apparently reasonable rigid principles of interpretation.

*Michael Kachelriess*

- Published in print:
- 2017
- Published Online:
- February 2018
- ISBN:
- 9780198802877
- eISBN:
- 9780191841330
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780198802877.003.0023
- Subject:
- Physics, Particle Physics / Astrophysics / Cosmology, Theoretical, Computational, and Statistical Physics

After a review of conformal symmetry, this chapter covers the quantisation of fields in curved space-times. It is shown that field operators defined with respect to different vacua are related by a ...
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After a review of conformal symmetry, this chapter covers the quantisation of fields in curved space-times. It is shown that field operators defined with respect to different vacua are related by a Bogolyubov transformation and that the mixing of positive and negative frequencies determines the amount of particle production. The Unruh effect is explained and it is shown that in a space-time with an event horizon, a thermal spectrum of particles is created close to the horizon.Less

After a review of conformal symmetry, this chapter covers the quantisation of fields in curved space-times. It is shown that field operators defined with respect to different vacua are related by a Bogolyubov transformation and that the mixing of positive and negative frequencies determines the amount of particle production. The Unruh effect is explained and it is shown that in a space-time with an event horizon, a thermal spectrum of particles is created close to the horizon.