Original language | English |
---|---|
Pages (from-to) | 171-189 |
Number of pages | 19 |
Journal | Acta Mathematica |
Volume | 183 |
Issue number | 2 |
DOIs | |
State | Published - 1999 |
Bibliographical note
Funding Information:Acknowledgments. We would like to thank J. Avron and B. Simon for useful discussions. The first author is an Alfred P. Sloan Research Fellow, and was supported in part by NSF Grants DMS-9501265 and DMS-9704130. The second author was supported in part by NSF Grant DMS-9801474.