Editing Inflaton (section)

== Non-minimally coupled inflation <!--'Non-minimally coupled inflation' redirects here--> ==
'''Non-minimally coupled inflation'''<!--boldface per WP:R#PLA--> is an [[cosmic inflation|inflationary]] model in which the constant which couples [[gravity]] to the [[inflaton field]] is not small. The [[coupling constant]] is usually represented by <math>\xi</math> (letter ''[[xi (letter)|xi]]''), which features in the [[action (physics)|action]] (constructed by modifying the [[Einstein–Hilbert action]]):<ref name="hertzberg12">{{Cite journal |last=Hertzberg |first=Mark P. |date=2010 |title=On Inflation with Non-minimal Coupling |journal=Journal of High Energy Physics |volume=2010 |issue=11 |pages=23 |arxiv=1002.2995 |bibcode=2010JHEP...11..023H |doi=10.1007/JHEP11(2010)023 |s2cid=54886582}}
</ref>{{rp|1&ndash;2}}
: <math>S = \int d^4x \sqrt{-g} \left[ \tfrac{1}{2} m_P^2 R - \tfrac{1}{2}\partial^{\mu}\phi \partial_{\mu}\phi 
- V(\phi) - \tfrac{1}{2} \xi R \phi^2\right] ,</math>
with <math>\xi</math> representing the strength of the interaction between <math>R</math> and {{tmath|1= \phi }}, which respectively relate to the curvature of space and the magnitude of the inflaton field.