Modified hybrid inflation in no-scale SUGRA with suppressed R-symmetry breaking

Qian Wan; Da-Xin Zhang

doi:10.1140/epjc/s10052-025-13911-w

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2023 Impact factor 4.2

Particles and Fields

Open Access

Eur. Phys. J. C (2025) 85: 194
https://doi.org/10.1140/epjc/s10052-025-13911-w

Regular Article - Theoretical Physics

Modified hybrid inflation in no-scale SUGRA with suppressed R-symmetry breaking

Qian Wan^a and Da-Xin Zhang

School of Physics, Peking University, 100871, Beijing, China

^a wanqian@pku.edu.cn

Received: 28 August 2024
Accepted: 10 February 2025
Published online: 18 February 2025

Abstract

A well-motivated cosmological hybrid inflation scenario based on no-scale SUGRA is considered. It is demonstrated that an extra suppressed R-symmetry breaking term $S^{n}$ $$S^n$$ with $n \geq 4$ $n\ge 4$ needs to be included in order to realize successful inflation. The resulting potential is found to be similar (but not identical) to the one in the Starobinsky inflation model. A relatively larger tensor-to-scalar ratio $r \sim 10^{- 2}$ $r\sim 10^{-2}$ and a spectral index $n_{s} \approx 0.965$ $n_s\approx 0.965$ are obtained, which are approximately independent of n.

© The Author(s) 2025

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