English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

This thesis investigates a toy model for inflation in a class of modifiedtheories of gravity in the metric formalism. Instead of the standard procedure-- assuming a non-linear Lagrangian $f(R)$ in the Jordan frame -- we start froma simple {\phi}^2 potential in the Einstein frame and investigate thecorresponding $f(R)$ in the former picture. Such approach yields plenty of newpieces of information, namely a self-terminating inflationary solution with alinear Lagrangian, a robust criterion for stability of such theories, adynamical effective potential for the Ricci scalar $R$, the addition of anad-hoc Cosmological Constant in the Einstein frame leads to a Thermodynamicalinterpretation of this physical system, which allows further insight on its(meta)stability and evolution.

Study of General Relativity and $f(R)$ Modified Gravity with Cosmological Constant for Einstein and Jordan Frames