A note on -operators of order 2
Tom 170 / 2022
Streszczenie
It is known that G-functions solving a linear differential equation of order 1 with coefficients in \overline {\mathbb Q}(z) are algebraic (and of a very precise form). No general result is known when the order is 2. In this paper, we determine the form of a G-function solving an inhomogeneous equation of order 1 with coefficients in \overline {\mathbb Q}(z), as well as that of a G-function f of differential order 2 over \overline {\mathbb Q}(z) and such that f and f’ are algebraically dependent over \mathbb C(z). Our results apply more generally to holonomic Nilsson–Gevrey arithmetic series of order 0 that encompass G-functions.