[ Homepage | Publications | Talks | TeXmacs |
Mathemagix ] |

Let denote the ring of
analytic -periodic functions
in on the real axis. Let
denote the ring of formal
Laurent series in , whose
coefficients are defined on a *common* strip neighbourhood of the
real axis. In this paper, we study the linear differential equation

with coefficients in . We prove that, after a change of variables with and , this equation admits a basis of formal solutions of the form

where , and . This generalizes a well known result when is replaced by .

**View:** Gzipped Postscript, BibTeX