de Sitter swampland conjecture in string field inflation J. Sadeghi, B. Pourhassan, S. Noori Gashti, İ. Sakallı and M. R. Alipour Eur. Phys. J. C, 83 7 (2023) 635 Published online: 18 July 2023 DOI: 10.1140/epjc/s10052-023-11822-2