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arXiv · 2411.08031

$\tildeξ$-attractors in metric-affine gravity

Antonio Racioppi
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Abstract

We propose a new class of inflationary attractors in metric-affine gravity. Such class features a non-minimal coupling $\tildeξ\, Ω(ϕ)$ with the Holst invariant $\tilde{\cal R}$ and an inflaton potential proportional to $Ω(ϕ)^2$. The attractor behaviour of the class takes place with two combined strong coupling limits. The first limit is realized at large $\tildeξ$, 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 $ξ$-attractors, we label this new class as $\tildeξ$-attractors.

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Antonio Racioppi. 2025-07-02. $\tildeξ$-attractors in metric-affine gravity. https://doi.org/10.1088/1475-7516%2F2025%2F04%2F084

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