Abstract
We prove that a certain positivity condition, considerably more general than pseudoconvexity, enables one to conclude that the regular and singular orders of contact agree when either of these numbers is 4.
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References
Brinzanescu, V., Nicoara, A.: On the relationship between D’Angelo q-type and Catlin q-type. J. Geom. Anal. 25(3), 1701–1719 (2015)
Brinzanescu, V., Nicoara, A.: Relating Catlin and D’Angelo q-types, Math arXiv:1707.08294
Boas, H.P., Straube, E.J.: On equality of line type and variety type of real hypersurfaces in \({\mathbb{C}}^n\). J. Geom. Anal. 2(2), 95–98 (1992)
Catlin, D.: Subelliptic estimates for the \({\overline{\partial }}\)-Neumann problem on pseudoconvex domains. Ann. Math. (2) 126(1), 131–191 (1987)
D’Angelo, J.P.: Several Complex Variables and the Geometry of Real Hypersurfaces. CRC Press, Boca Raton, FL (1992)
D’Angelo, J.P.: Real hypersurfaces, orders of contact, and applications. Ann. Math. (2) 115(3), 615–637 (1982)
Diederich, K., Fornaess, J.E.: Pseudoconvex domains with real-analytic boundary. Ann. Math. (2) 107(2), 371–384 (1978)
Fassina, M.: The relationship between two notions of order of contact, preprint
Fu, S., Isaev, A., Krantz, S.: Finite type conditions on Reinhardt domains. Complex Var. Theory Appl. 31(4), 357–363 (1996)
Kohn, J.J.: Subellipticity of the \({\overline{\partial }}\)-Neumann problem on pseudoconvex domains: sufficient conditions. Acta Math. 142(1–2), 79–122 (1979)
McNeal, J.D.: Convex domains of finite type. J. Funct. Anal. 108(2), 361–373 (1992)
Mernik, L., McNeal, J.: Regular versus singular order of contact on pseudoconvex hypersurfaces, Math arXiv:1708.02673
Zaitsev, D.: A geometric approach to Catlin’s boundary systems, Math arXiv: 1704.01808
Acknowledgements
The author thanks the referee for suggesting some clarifications. The author particularly thanks Jeff McNeal for noting the author’s omission in [5] and for sharing versions of the preprint [12] with him. The author acknowledges useful discussions with Dmitri Zaitsev, Siqi Fu, and Ming Xiao. The important preprint [13] by Zaitsev makes a systematic study of fourth-order invariants, but it does not include our Theorem 1.1. The author acknowledges support from NSF Grant DMS 13-61001.
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D’Angelo, J.P. A Remark on Finite Type Conditions. J Geom Anal 28, 2602–2608 (2018). https://doi.org/10.1007/s12220-017-9921-1
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DOI: https://doi.org/10.1007/s12220-017-9921-1
Keywords
- Finite type conditions
- Positivity property
- Plurisubharmonic function
- Real hypersurface germ
- Faa di Bruno formula