From theory to observation: Swampland conjectures and ACT constraints on marginally deformed R2 inflation

This work investigates the viability of marginally deformed ( R 2 ) inflation within the framework of the swampland program. The analysis focuses on the Further Refined de Sitter Swampland Conjecture (FRDSSC), the Scalar Weak Gravity Conjecture (SWGC), and its strong extension, the Strong Scalar Weak Gravity Conjecture (SSWGC). By confronting theoretical predictions with observational constraints, the study examines how variations in the model parameters influence its consistency with these conjectures. The results indicate that the model remains compatible with the FRDSSC across a broad region of the parameter space and aligns well with current cosmological observations, supporting its viability as an inflationary framework. Moreover, the comparison between the SWGC and SSWGC reveals that the compatibility of the model is highly sensitive to changes in the coupling parameters, with the SSWGC generally allowing a wider range of consistency than the SWGC. This finding suggests that the stronger conjecture encompasses a broader domain of theoretical validity. Overall, the marginally deformed ( R 2 ) inflation model satisfies all considered swampland criteria, reinforcing its theoretical robustness and its potential as a compelling inflationary scenario within the landscape of quantum gravity-compatible models.