@article{62171eb74bd44006b52910c3be6b240c,
title = "Perturbation theory for infinite-dimensional integrable systems on the line. A case study",
author = "Percy Deift and Xin Zhou",
note = "Funding Information: Acknowledgments. The authors are especially grateful to Jalal Shatah for bringing the normal form problem for equation (1.1) to our attention and for many extremely helpful discussions. The authors would also like to thank Henry McKean, David McLaughlin, Randall Pyke and John Harnad for providing us with additional useful information. The first author was supported in part by NSF Grants DMS-9500867, 0003268, and the second author was supported in part by NSF Grants DMS-9401403, 9706644, 0071398. The work was also supported in part by the Institute for Advanced Study and the Guggenheim Foundation (both authors), and by the Courant Institute (second author).",
year = "2002",
doi = "10.1007/BF02392683",
language = "English (US)",
volume = "188",
pages = "163--262",
journal = "Acta Mathematica",
issn = "0001-5962",
publisher = "Springer Netherlands",
number = "2",
}