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A family of degenerate differential operators

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Abstract

Certain second-order partial differential operators, expressed as sums of squares of complex vector fields, are shown not to beC ∞ hypoelliptic even at a point, rather than merely in an open set. The proof is based on an asymptotic analysis of a family of ordinary differential operators depending on a complex parameter.

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Authors and Affiliations

  1. Department of Mathematics, UCLA, 90024, Los Angeles, CA

    Michael Christ

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  1. Michael Christ
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Research supported by the National Science Foundation.

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Christ, M. A family of degenerate differential operators. J Geom Anal 3, 579–597 (1993). https://doi.org/10.1007/BF02921323

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  • DOI: https://doi.org/10.1007/BF02921323

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