30 June 2025 to 4 July 2025
University of Tartu
Europe/Tallinn timezone

$\tilde\xi$-attractors in metric-affine gravity

Not scheduled
20m
Physicum (University of Tartu)

Physicum

University of Tartu

W. Ostwaldi 1, Tartu 50411, Estonia
Talk Contributed talks

Speaker

Antonio Racioppi (National Institute of Chemical Physics and Biophysics (EE))

Description

We propose a new class of inflationary attractors in metric-affine gravity. Such class features a non-minimal coupling $\tilde\xi \, \Omega(\phi)$ with the Holst invariant $\tilde {\cal R}$ and an inflaton potential proportional to $\Omega(\phi)^2$. The attractor behaviour of the class takes place with two combined strong coupling limits. The first limit is realized at large $\tilde\xi$, which makes the theory equivalent to a $\tilde {\cal R}^2$ model. Then, the second limit considers a very small Barbero-Immirzi parameter which leads the inflationary predictions of the $\tilde {\cal R}^2$ model towards the ones of Starobinsky inflation. Because of the analogy with the renown $\xi$-attractors, we label this new class as $\tilde\xi$-attractors.

Author

Antonio Racioppi (National Institute of Chemical Physics and Biophysics (EE))

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