Exact Keldysh theory of strong-field ionization: residue method vs saddle-point approximation

Yulian V. Vanne, Alejandro Saenz

In recent articles [Mishima et al., Phys. Rev. A, 66, 033401(2002); Chao, Phys. Rev. A, 72, 053414 (2005)] it was proposed to use the residue theorem for the exact calculation of t…