Modeling femtosecond pulse propagation and high harmonics generation in hollow core fibers Valer Tosa, Anna Gabriella Ciriolo, Rebeca Martinez Vazquez, Caterina Vozzi and Salvatore Stagira EPJ Web Conf., 255 (2021) 11005 Published online: 18 November 2021 DOI: 10.1051/epjconf/202125511005