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\begin{document}

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\section*{eternal inflation}

\hypertarget{context}{}\subsubsection*{{Context}}\label{context}

\hypertarget{physics}{}\paragraph*{{Physics}}\label{physics}

[[!include physicscontents]]

\hypertarget{contents}{}\section*{{Contents}}\label{contents}

\noindent\hyperlink{idea}{Idea}\dotfill \pageref*{idea} \linebreak
\noindent\hyperlink{implications}{Implications}\dotfill \pageref*{implications} \linebreak
\noindent\hyperlink{references}{References}\dotfill \pageref*{references} \linebreak


\hypertarget{idea}{}\subsection*{{Idea}}\label{idea}

In the context of [[cosmic inflation]] one speaks of \emph{eternal inflation} if the inflationary expansion process perpetuates, in space and/or time.

Many classes of models of [[cosmic inflation]] in fact exhibit eternal inflation, notably the observationally preferred plateau-models, such as the [[Starobinsky model of cosmic inflation]] (\hyperlink{BarenboimKinneyPark16}{Barenboim-Kinney-Park 16}). (Also models of [[chaotic inflation]] do, but these are now strongly disfavoured by [[experiment|observation]]).

\hypertarget{implications}{}\subsection*{{Implications}}\label{implications}

The idea of eternal cosmic inflation has been argued to provide a possible way to conceptualize the measured values of dimensionless ``physical constants'', such as the [[fine structure constant]], the [[Yukawa couplings]] and notably the [[cosmological constant]]: for if in the fundamental [[theory (physics)|theory]] these parameters are not really constants but are dynamical [[field (physics)|fields]] that just happen to have constant value (``moduli fields'') over large scales, then they might, so the argument, still vary from one ``inflationary bubble'' to the next. Thereby the idea of eternal inflation combined with that of a fundamental theory that has [[moduli fields]] (such as [[string theory]] with its [[landscape of string theory vacua]]) has been argued to put ``physical constants'' on the same footing as other more or less random phenomenological parameters, such as for instance the distance of our planets from the sun, etc.

For more on this see at \emph{[[multiverse]]}.

\hypertarget{references}{}\subsection*{{References}}\label{references}

\begin{itemize}%
\item [[Alexander Vilenkin]], \emph{Birth of inflationary universes}, Phys. Rev. D 27, 2848 (\href{https://doi.org/10.1103/PhysRevD.27.2848}{doi:10.1103/PhysRevD.27.2848})


\item [[Aleksei Starobinsky]], \emph{Stochastic de sitter (inflationary) stage in the early universe}, In: de Vega H.J., Sánchez N. (eds) Field Theory, Quantum Gravity and Strings. Lecture Notes in Physics, vol 246. Springer, Berlin, Heidelberg (\href{https://doi.org/10.1007/3-540-16452-9_6}{doi:10.1007/3-540-16452-9\_6})


\item [[Alan Guth]], \emph{Eternal inflation and its implications}, J.Phys.A40:6811-6826, 2007 (\href{https://arxiv.org/abs/hep-th/0702178}{arXivL:hep-th/0702178})


\item Gabriela Barenboim, [[William Kinney]], Wan-Il Park, \emph{Eternal Hilltop Inflation}, Journal of Cosmology and Astroparticle Physics, Volume 2016, May 2016 (\href{https://arxiv.org/abs/1601.08140}{arXiv:1601.08140})



\end{itemize}
See also

\begin{itemize}%
\item Wikipedia, \emph{\href{https://en.wikipedia.org/wiki/Eternal_inflation}{Eternal inflation}}

\end{itemize}
[[!redirects eternal cosmic inflation]]



\end{document}