TY - JOUR AU - Lastra,A. AU - Michalik,S. AU - Suwi?ska,M. KW - Formal automorphism KW - Gevrey series KW - Integro-differential operator KW - Moment differentiation KW - Newton polygon T1 - On conditions determining formal automorphisms of integro-differential operators LA - eng PY - 2026/04/01/ T2 - Aequationes Mathematicae SN - 1420-8903 VL - 100 IS - 2 PB - Springer International Publishing AB - Results providing conditions on a family of integro-differential operators to determine a formal automorphism are established. Equivalently, the problem can be read in terms of existence and uniqueness of formal solutions of Cauchy problems in different settings. The main achievements provide a three-statement result not only in the framework of general formal power series, but also on subspaces appearing in applications such as Gevrey settings and moment differential operators. DO - 10.1007/S00010-026-01281-X UR - https://portalcientifico.uah.es/documentos/69ed6850fcbcf03d32be909a DP - Dialnet - Portal de la Investigación ER -