RT journal article T1 First Integrals of Differential Operators from SL(2, R) Symmetries A1 Morando, Paola A1 Muriel Patino, María Concepción A1 Ruiz Serván, Adrián A2 Matemáticas K1 differential operator K1 first integral K1 solvable structure K1 integrable distribution AB The construction of first integrals for SL(2,R)-invariant nth-order ordinary differential equations is a non-trivial problem due to the nonsolvability of the underlying symmetry algebra sl(2,R). Firstly, we provide for n=2 an explicit expression for two non-constant first integrals through algebraic operations involving the symmetry generators of sl(2,R), and without any kind of integration. Moreover, although there are cases when the two first integrals are functionally independent, it is proved that a second functionally independent first integral arises by a single quadrature. This result is extended for n>2, provided that a solvable structure for an integrable distribution generated by the differential operator associated to the equation and one of the prolonged symmetry generators of sl(2,R) is known. Several examples illustrate the procedures. PB MDPI SN 2227-7390 YR 2020 FD 2020-12 LK http://hdl.handle.net/10498/24359 UL http://hdl.handle.net/10498/24359 LA eng DS Repositorio Institucional de la Universidad de Cádiz RD 10-may-2026