Singular Linear Differential Equations in Two Variables

MR2493878 B. L. J. BRAAKSMA and M. van der PUT B. L. J. BRAAKSMA and M. van der PUT Singular Linear Differential Equations in Two Variables Funkcialaj Ekvacioj. Serio Internacia 51 2008 459--462 http://fe.math.kobe-u.ac.jp/FE/FullPapers/51-3/51_459.pdf http://www.ams.org/mathscinet-getitem?mr=MR2493878 The formal and analytic classification of integrable singular linear differential equations has been studied among others by R. Gérard and Y. Sibuya. We provide a simple proof of their main result, namely: For certain irregular systems in two variables there is no Stokes phenomenon, i.e. there is no difference between the formal and the analytic classification. Stokes phenomenon, Asymptotics, Singular differential equations in more variables. 35F05, 34E05, 34M40. 51-459 2008 Singular Linear Differential Equations in Two Variables B. L. J. BRAAKSMA and M. van der PUT B. L. J. BRAAKSMA and M. van der PUT

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