https://doi.org/10.1140/epjc/s10052-025-13982-9
Regular Article - Theoretical Physics
Back to the origins of brane–antibrane inflation
1
Dipartimento di Fisica e Astronomia, Università di Bologna, via Irnerio 46, 40126, Bologna, Italy
2
INFN, Sezione di Bologna, viale Berti Pichat 6/2, 40127, Bologna, Italy
3
DAMTP, University of Cambridge, Wilberforce Road, CB3 0WA, Cambridge, UK
4
Department of Theoretical Physics and Astrophysics, Masaryk University, Kotlářská 2, 61137, Brno, Czechia
5
Department of Mathematics and Natural Sciences, BRAC University, 66 Mohakhali, 1212, Dhaka, Bangladesh
6
CERN Theory Group, 1211, Geneva, Switzerland
7
New York University, PO Box 129188, Abu Dhabi, Saadiyat Island, UAE
Received:
19
October
2024
Accepted:
12
February
2025
Published online:
18
March
2025
We study a new framework for brane–antibrane inflation where moduli stabilisation relies purely on perturbative corrections to the effective action. This guarantees that the model does not suffer from the eta-problem. The inflationary potential has two contributions: the tension of an antibrane at the tip of a warped throat, and its Coulomb interaction with a mobile brane. This represents the first realisation of the original idea of brane–antibrane inflation, as opposed to inflection point inflation which arises when the moduli are fixed with non-perturbative effects. Moreover, we formulate the brane–antibrane dynamics as an F-term potential of a nilpotent superfield in a manifestly supersymmetric effective theory. We impose compatibility with data and consistency conditions on control over the approximations and find that slow-roll inflation can occur in a large region of the underlying parameter space. The scalar spectral index is in agreement with data and the tensor-to-scalar ratio is beyond current observational reach. Interestingly, after the end of inflation the volume mode can, but does not need to, evolve towards a late-time minimum at larger values.
© The Author(s) 2025
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