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

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

30 Jun 2025, 15:40
25m
A101 (University of Tartu, Physicum)

A101

University of Tartu, Physicum

W. Ostwaldi 1, Tartu 50411, Estonia
Talk Contributed talks Monday Parallel 4 - A101

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))

Presentation materials