Editing Quantum gravity (section)

=== Other theories ===
There are a number of other approaches to quantum gravity. The theories differ depending on which features of general relativity and quantum theory are accepted unchanged, and which features are modified.<ref>{{Cite book
|last=Isham
|first=Christopher J.
|title=Canonical Gravity: From Classical to Quantum
|author-link=Christopher Isham
|contribution=Prima facie questions in quantum gravity
|editor-last=Ehlers
|editor-first=Jürgen
|editor2-last=Friedrich
|editor2-first=Helmut
|volume=434
|pages=1–21
|date=1994
|publisher=Springer
|arxiv=gr-qc/9310031
|isbn=978-3-540-58339-4
|bibcode=1994LNP...434....1I
|doi=10.1007/3-540-58339-4_13
|series=Lecture Notes in Physics
|s2cid=119364176
}}</ref><ref>{{Cite journal
|last=Sorkin
|first=Rafael D.
|author-link= Rafael Sorkin
|title=Forks in the Road, on the Way to Quantum Gravity
|arxiv=gr-qc/9706002
|journal=[[International Journal of Theoretical Physics]]
|volume=36
|date=1997
|issue=12
|pages=2759–2781
|doi=10.1007/BF02435709
|bibcode = 1997IJTP...36.2759S |s2cid=4803804
}}</ref> Such theories include:
{{columns-list|colwidth=17em|
* [[Asymptotic safety in quantum gravity]]
* [[Euclidean quantum gravity]]
* [[Virtual black hole|Integral method]]<ref>{{Cite web |last=Klimets |first=A. P. |date=2017 |title=Philosophy Documentation Center, Western University – Canada |url=https://philpapers.org/archive/ALXOTF.pdf |url-status=live |archive-url=https://web.archive.org/web/20190701011840/https://philpapers.org/archive/ALXOTF.pdf |archive-date=2019-07-01 |access-date=2020-04-24 |publisher=Philosophy Documentation Center, Western University – Canada |pages=25–32}}</ref>
* [[Causal dynamical triangulation]]<ref>{{Cite journal
|last=Loll
|first=Renate
|title=Discrete Approaches to Quantum Gravity in Four Dimensions
|journal=[[Living Reviews in Relativity]]
|volume=1
|issue=1
|page=13
|date=1998
|bibcode=1998LRR.....1...13L
|arxiv = gr-qc/9805049 |doi = 10.12942/lrr-1998-13 |doi-access=free
|pmid=28191826
 |pmc=5253799
}}</ref>
* [[Causal fermion system]]s
* [[causal sets|Causal Set Theory]]
* Covariant Feynman [[path integral formulation|path integral]] approach
* [[Dilaton#The dilaton in quantum gravity|Dilatonic quantum gravity]]
*[[Double copy theory]]
* [[Group field theory]]
* [[Wheeler–DeWitt equation]]
* [[Geometrodynamics]]
* [[Hořava–Lifshitz gravity]]
* [[MacDowell–Mansouri action]]
* [[noncommutative standard model|Noncommutative geometry]]
* [[path integral formulation|Path-integral]] based models of [[quantum cosmology]]<ref>{{Cite book
|last=Hawking
|first=Stephen W.
|author-link=Stephen Hawking
|contribution=Quantum cosmology
|pages =631–651
|editor2-last=Israel
|editor2-first=Werner
|editor1-last=Hawking
|editor1-first=Stephen W.
|title=300 Years of Gravitation
|publisher=Cambridge University Press
|date=1987
|isbn=978-0-521-37976-2
}}</ref>
* [[Regge calculus]]
* [[Shape dynamics|Shape Dynamics]]
* [[String-net]]s and [[quantum graphity]]
* [[Supergravity]]
* [[Twistor theory]]<ref>See ch. 33 in {{Harvnb|Penrose|2005}} and references therein.</ref>
* [[Canonical quantum gravity]]
}}