“Horndeski's theory”的意思、由来-开放百科全书

Horndeski's theory is the most general theory of gravity in four dimensions whose Lagrangian is constructed out of the metric tensor and a scalar field and leads to second order equations of motion{{clarify|date=November 2017|reason=Second order in what?}}. The theory was first proposed by Gregory Horndeski in 1974^[1] and has found numerous applications, particularly in the construction of cosmological models of Inflation and dark energy.^[2] Horndeski's theory contains many theories of gravity, including General relativity, Brans-Dicke theory, Quintessence, Dilaton, Chameleon and covariant Galileon^[3] as special cases.

Here

is Newton's constant,

represents the matter Lagrangian,

are generic functions of

and

are the Ricci scalar and Einstein tensor,

is the Jordan frame metric, semicolon indicates covariant derivatives, commas indicate partial derivatives,

and repeated indices are summed over following Einstein's convention.

The free parameters of the theory, especially the contributions from

and

, are strongly constrained by the direct measurement of the speed of gravitational waves following GW170817.^[5]^[6]^[7]^[8]^[9]^[10]

See also

References

1. ^{{Cite journal|last=Horndeski|first=Gregory Walter|date=1974-09-01|title=Second-order scalar-tensor field equations in a four-dimensional space|journal=International Journal of Theoretical Physics|language=en|volume=10|issue=6|pages=363–384|doi=10.1007/BF01807638|issn=0020-7748|bibcode=1974IJTP...10..363H}}
2. ^{{Cite journal|last=Clifton|first=Timothy|last2=Ferreira|first2=Pedro G.|last3=Padilla|first3=Antonio|last4=Skordis|first4=Constantinos|date=March 2012|title=Modified Gravity and Cosmology|journal=Physics Reports|volume=513|issue=1–3|pages=1–189|doi=10.1016/j.physrep.2012.01.001|arxiv=1106.2476|bibcode=2012PhR...513....1C}}
3. ^{{Cite journal|last=Deffayet|first=C.|last2=Esposito-Farese|first2=G.|last3=Vikman|first3=A.|date=2009-04-03|title=Covariant Galileon|journal=Physical Review D|volume=79|issue=8|pages=084003|doi=10.1103/PhysRevD.79.084003|issn=1550-7998|arxiv=0901.1314|bibcode=2009PhRvD..79h4003D}}
4. ^{{Cite journal|last=Kobayashi|first=Tsutomu|last2=Yamaguchi|first2=Masahide|last3=Yokoyama|first3=Jun'ichi|date=2011-09-01|title=Generalized G-inflation: Inflation with the most general second-order field equations|journal=Progress of Theoretical Physics|volume=126|issue=3|pages=511–529|doi=10.1143/PTP.126.511|issn=0033-068X|arxiv=1105.5723|bibcode=2011PThPh.126..511K}}
5. ^{{Cite journal|last=Lombriser|first=Lucas|last2=Taylor|first2=Andy|date=2016-03-16|title=Breaking a Dark Degeneracy with Gravitational Waves|journal=Journal of Cosmology and Astroparticle Physics|volume=2016|issue=3|pages=031|doi=10.1088/1475-7516/2016/03/031|issn=1475-7516|arxiv=1509.08458|bibcode=2016JCAP...03..031L}}
6. ^{{Cite journal|last=Bettoni|first=Dario|last2=Ezquiaga|first2=Jose María|last3=Hinterbichler|first3=Kurt|last4=Zumalacárregui|first4=Miguel|date=2017-04-14|title=Speed of Gravitational Waves and the Fate of Scalar-Tensor Gravity|journal=Physical Review D|volume=95|issue=8|pages=084029|doi=10.1103/PhysRevD.95.084029|issn=2470-0010|arxiv=1608.01982|bibcode=2017PhRvD..95h4029B}}
7. ^{{cite journal|last=Creminelli|first=Paolo|last2=Vernizzi|first2=Filippo|date=2017-10-16|title=Dark Energy after GW170817|journal=Physical Review Letters|volume=119|issue=25|pages=251302|arxiv=1710.05877|doi=10.1103/PhysRevLett.119.251302|pmid=29303308}}
8. ^{{cite journal|last=Sakstein|first=Jeremy|last2=Jain|first2=Bhuvnesh|date=2017-10-16|title=Implications of the Neutron Star Merger GW170817 for Cosmological Scalar-Tensor Theories|journal=Physical Review Letters|volume=119|issue=25|pages=251303|arxiv=1710.05893|doi=10.1103/PhysRevLett.119.251303|pmid=29303345}}
9. ^{{Cite journal|last=Ezquiaga|first=Jose María|last2=Zumalacárregui|first2=Miguel|date=2017-12-18|title=Dark Energy After GW170817: Dead Ends and the Road Ahead|journal=Physical Review Letters|volume=119|issue=25|pages=251304|arxiv=1710.05901|doi=10.1103/PhysRevLett.119.251304|pmid=29303304|bibcode=2017PhRvL.119y1304E}}
10. ^{{Cite news|url=https://www.sciencenews.org/article/what-detecting-gravitational-waves-means-expansion-universe|title=What detecting gravitational waves means for the expansion of the universe|last=Grossman|first=Lisa|date=2017-10-24|work=Science News|access-date=2017-11-08|language=en}}