M. Poppenberg, NEGATIVE RESULTS ON THE NASH-MOSER THEOREM FOR KOTHE SEQUENCE-SPACES AND FOR SPACES OF ULTRADIFFERENTIABLE FUNCTIONS, Manuscripta mathematica, 90(4), 1996, pp. 465-478
Counterexamples to the Nash-Moser inverse function theorem are given f
or Kothe sequence spaces extending a result of Lojasiewics and Zehnder
. As an application also negative results are obtained for spaces of u
ltradifferentiable functions of Beurling type, in particular for the G
evrey classes.