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Symplectic geometry and positivity of pseudo-differential operators

C Fefferman1, D H Phong

  • 1Department of Mathematics, Princeton University, Princeton, New Jersey 08544-0037.

Proceedings of the National Academy of Sciences of the United States of America
|January 1, 1982
PubMed
Summary

This study establishes necessary and sufficient conditions for the positivity of pseudo-differential operators. The findings are based on advanced microlocalization techniques and a novel geometric lemma.

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