Physics:Quantum field theory in curved spacetime
Quantum field theory in curved spacetime studies quantum fields on a classical curved spacetime background. It is not a full theory of quantum gravity because the geometry is not itself quantized, but it captures important effects where matter fields are quantum while gravity is treated classically. It is central to Hawking radiation, the Unruh effect, cosmological particle creation, and semiclassical gravity.[1][2]
No unique particle concept
In flat spacetime, particles can often be defined using preferred modes and a preferred vacuum. In curved spacetime this definition can become observer-dependent or background-dependent, so the vacuum and particle content may not be unique.[3]
Important predictions
The framework predicts phenomena such as particle creation in expanding universes and Hawking radiation from black holes. These effects show how quantum fields can respond to horizons, acceleration, and changing geometry.[4]
Intermediate theory
QFT in curved spacetime is an intermediate step toward quantum gravity. It is expected to work when spacetime curvature is not Planckian and when the quantum fields do not strongly back-react on the geometry.[5]
Description
field theory in curved spacetime is a matter-scale concept used to organize how quantum theory describes atoms, particles, fields, condensed matter, plasma, or spacetime-related systems. In the Quantum Collection it is placed by scale so the reader can move from materials and molecules down to subatomic degrees of freedom.
Quantum context
At this scale, the relevant behavior is controlled by quantized states, interactions, conservation laws, and the way excitations or particles are observed. The concept is normally linked to measurable properties such as energy, momentum, charge, spin, spectra, scattering rates, or collective modes.
Role in the collection
This page provides a compact reference point for related pages in Book II. It should be read together with nearby matter-scale topics and the corresponding foundations in quantum mechanics.[6]
See also
Table of contents (84 articles)
Index
Full contents
References
- ↑ "Quantum field theory in curved spacetime". https://en.wikipedia.org/wiki/Quantum_field_theory_in_curved_spacetime.
- ↑ Wald, Robert M. (1994). Quantum Field Theory in Curved Spacetime and Black Hole Thermodynamics. University of Chicago Press. ISBN 978-0-226-87027-4.
- ↑ Birrell, N. D.; Davies, P. C. W. (1982). Quantum Fields in Curved Space. Cambridge University Press. ISBN 978-0-521-27858-4.
- ↑ Wald, Robert M. (1994). Quantum Field Theory in Curved Spacetime and Black Hole Thermodynamics. University of Chicago Press. ISBN 978-0-226-87027-4.
- ↑ Rovelli, Carlo (2004). Quantum Gravity. Cambridge University Press. ISBN 978-0-521-83733-0.
- ↑ "Quantum mechanics". https://en.wikipedia.org/wiki/Quantum_mechanics.
Source attribution: Physics:Quantum field theory in curved spacetime