Mishaal Hai | Searcharxiv

arXiv2026

Effect of Moduli Redefinitions on Fibre Inflation

In this paper, we have discovered a new avenue of fibre inflation in perturbative large volume scenario (pLVS) due to the redefinition of the base modulus. pLVS offers a novel regime where large volume of the internal space is guaranteed without the need of non-perturbative effects. In this setup, we study the possibility where a base redefinition allows to assess different versions of fibre inflation whose spectral index aligns with Atacama Cosmology Telescope (ACT) data and produces tensor-to-scalar ratio in the range $0.008\lesssim r\lesssim 0.01$ in different setups we have considered. The leading order flat direction - which in our case is the fibre modulus - is lifted with the combinations of string loop corrections, leading order $α^{\prime 3}$$R^4$-correction, higher derivative $F^{4}$ corrections as well as our new ingredient redefinition of the modulus. Since recent Dark Energy Spectroscopic Instrument (DESI) results appear to favour a dynamical explanation for late-time acceleration over a simple cosmological constant, exploring quintessence offers a more suitable approach. In this lore, we also examine the quintessence sector to complete our model and account for both early- and late-time cosmic acceleration. In this framework, the poly-instanton correction generates a potential along the axionic directions, and we find that the resulting quintessence behaviour and the subsequent cosmological predictions about dark matter closely resemble the predictions of the original fibre inflation scenario studied earlier.

hep-th↗

arXiv2025

Perturbative Kähler Moduli Inflation

In this work, we present two classes of inflationary models in the framework of type IIB string theory. The inflatons correspond to blow-up Kähler modulus arising from compactifying type IIB string theory on a Calabi-Yau. Using perturbative corrections, we first highlight a procedure for stabilising more than one Kähler modulus. For the case of two Kähler moduli, we explicitly construct two classes of inflationary potentials within the Kähler cone which satisfy both EFT and cosmological constraints. The first class of models, arising from moduli redefinition of the blow-up mode, garners a potential of the form $V(ϕ)=V_{0}(1+C_{1} ϕ^{2/3})$ align with CMB data with scalar-to-tensor ratio $r\lesssim 10^{-2}$. The second class of models, which have been recently proposed as loop blow-up inflation, have a form $V(ϕ)=V_{0}(1+C_{2}ϕ^{-2/3})$, also agrees with CMB data with scalar-to tensor-ratio $r\lesssim 10^{-8}$. Our work differs from the original loop blow-up inflation in terms of stabilization mechanism and subsequently the scalar-to tensor ratio.

hep-th↗