# Euclidean quantum gravity

- Euclidean quantum gravity
**Euclidean quantum gravity** refers to a Wick rotated version of quantum gravity, formulated as a quantum field theory. The manifolds that are used in this formulation are 4 dimensional Riemannian manifolds instead of pseudo Riemannian manifolds. It is also assumed that the manifolds are compact, connected and boundaryless (i.e. no singularities). Following the usual quantum field-theoretic formulation, the vacuum to vacuum amplitude is written as a functional integral over the metric tensor, which is now the quantum field under consideration.

:$int\; mathcal\{D\}old\{g\},\; mathcal\{D\}phi,\; expleft(-int\; d^4x\; sqrt(R+mathcal\{L\}\_mathrm\{matter\})\; ight)$

where φ denotes all the matter fields. See Einstein-Hilbert action.

** References **

G. W. Gibbons and S. W. Hawking (eds.), *Euclidean quantum gravity* , World Scientific (1993)

*Wikimedia Foundation.
2010.*

### Look at other dictionaries:

**Loop quantum gravity** — Not to be confused with the path integral formulation of LQG, see spin foam. This article is about LQG in its Canonical formulation.. Beyond the Standard Model … Wikipedia

**Conformal gravity** — is a generic name for gravity theories which are invariant under conformal transformations in the Riemannian geometry sense; more accurately, they are invariant under Weyl transformations where gab is the metric tensor and Ω(x) is a function on… … Wikipedia

**Composite gravity** — In theoretical physics, composite gravity refers to models that attempted to derive general relativity in a framework where the graviton is constructed as a composite bound state of more elementary particles, usually fermions.A theorem by Steven… … Wikipedia

**Massive gravity** — In theoretical physics, massive gravity is a particular generalization of general relativity studied by Hendrik van Dam, Martinus J. G. Veltman (1) , and Vladimir E. Zakharov.(2) One assumes that physics takes place in Minkowski space and gravity … Wikipedia

**Causal dynamical triangulation** — Beyond the Standard Model Standard Model … Wikipedia

**Gary Gibbons** — Gary William Gibbons (born 1 July 1946), FRS, is a British theoretical physicist. Gibbons studied in Cambridge,where in 1969 he became a research student under the supervision of Dennis Sciama. When Sciama moved to Oxford, he became a student of… … Wikipedia

**Hawking radiation** — is a thermal radiation with a black body spectrum predicted to be emitted by black holes due to quantum effects. It is named after the physicist Stephen Hawking, who provided a theoretical argument for its existence in 1974, and sometimes also… … Wikipedia

**Holographic principle** — Holographic Universe redirects here. For the album, see Holographic Universe (album). For the book by Michael Talbot, see The Holographic Universe. String theory … Wikipedia

**AdS/CFT correspondence** — For the relation of the AdS/CFT correspondence to the general context of string theory, see String theory. The conformal field theory, which may be a gauge theory lies on the conformal boundary of anti deSitter space with quantum gravity. In… … Wikipedia

**Multiverse** — For other uses, see Multiverse (disambiguation). Physical cosmology … Wikipedia