Evolution of confined quantum scalar fields in curved spacetime. Part I - Spacetimes without boundaries or with static boundaries in a synchronous gaugeLuis C. Barbado, Ana L. Báez-Camargo and Ivette FuentesEur. Phys. J. C, 80 8 (2020) 796DOI: https://doi.org/10.1140/epjc/s10052-020-8369-9