Extension of CR maps between real-analytic hypersurfaces of different dimensions
Abstract
We consider a CR mapping \(f: M\rightarrow M'\) between real-analytic hypersurfaces of finite D’Angelo type in complex spaces \({\mathbb C}^{n+1}\) and \({\mathbb C}^{N+1}\), respectively, that extends as a holomorphic correspondence to a neighborhood of some point \(z_0\in M\) and that \(M'\) is Levi-nondegenerate at \(z_0'=f(z_0)\). In this paper, we give sufficient conditions to extend \(f\) as a holomorphic mapping across \(z_0\). In contrast with the equidimensional case, our result fails in general, when \(M'\) is Levi-degenerate at \(z_0'\). The proof uses the transversality of the mapping, which can be regarded as a type of Hopf’s lemma, the existence of points in \(M\) where the rank of the mapping is maximal; equal to \(n+1\) and the reflection principle in several variables. Related results were proved by Huang (Comm Partial Differ Equ 25:299–317, 2000); Pinchuk and Verma (Proc Am Math Soc 129(9):2623–2632, 2001); Diederich and Pinchuk (Doc Math 2:703–712, 1998); Diederich and Pinchuk (J Geom Anal 14(2):231–239, 2004) and Meylan et al. (Asian J Math 7(4):493–509, 2003).
Keywords
Analytic sets CR maps Holomorphic correspondences Segre varietiesMathematics Subject Classification (2010)
32H02 32H40 32H35 53C15Notes
Acknowledgments
The author would like to thank professor R. Shafikov for pointing out the Example 1 and the referee for his comments and suggestions which improved the paper greatly.
References
- 1.Baouendi, M.S., Ebenfelt, P., Rothschild, L.P.: Real submanifolds in complex space and their mappings, Princeton Math. Series 47, Princeton Univ. Press (1999)Google Scholar
- 2.Baouendi, M.S., Ebenfelt, P., Rothschild, L.P.: Algebraicity of holomorphic mappings between real algebraic sets in \({\mathbb{C}}^n\). Acta Math. 177(2), 225–273 (1996)CrossRefMathSciNetMATHGoogle Scholar
- 3.Baouendi, M.S., Ebenfelt, P., Rothschild, L.P.: Transversality of holomorphic mappings between real hypersurfaces in different dimensions. Comm. Anal. Geom. 15(3), 589–611 (2007)CrossRefMathSciNetMATHGoogle Scholar
- 4.Baouendi, M.S., Jacobowitz, H., Trèves, F.: On the analyticity of CR mappings. Ann. Math. 122, 365–400 (1985)CrossRefMATHGoogle Scholar
- 5.Baouendi, M.S., Rothschild, L.P.: Germs of CR maps between real-analytic hypersurfaces. Invent. Math. 93, 481–500 (1988)CrossRefMathSciNetMATHGoogle Scholar
- 6.Boggess, A.: CR manifold and the tangential Cauchy–Riemann complex. Stud. Adv. Math (1991)Google Scholar
- 7.Chirka, E.M.: Complex Analytic Sets. Kluwer Academic Publishers, Dordrecht, The Netherlands (1989)Google Scholar
- 8.Coupet, B., Damour, S., Merker, J., Sukhov, A.: Sur l’analyticité des applications CR lisses à valeurs dans un ensemble algébrique réel. C. R. Math. Acad. Sci. Paris 334(11), 953–956 (2002)CrossRefMathSciNetMATHGoogle Scholar
- 9.D’Angelo, J.: Real hypersurfaces, orders of contact, and applications. Ann. Math. 115, 615–637 (1982)CrossRefMathSciNetMATHGoogle Scholar
- 10.Derridj, M.: Le principe de réflexion en des points de faible pseudoconvexité pour des applications holomorphes propres. Invent. Math. 79, 197–215 (1985)CrossRefMathSciNetMATHGoogle Scholar
- 11.Diederich, K., Fornaess, J.E.: Proper holomorphic mappings between real-analytic pseudoconvex domains in \({\mathbb{C}}^n\). Math. Ann. 282(4), 681–700 (1988)CrossRefMathSciNetMATHGoogle Scholar
- 12.Diederich, K., Fornaess, J.E.: Pseudoconvex domains with real-analytic boundaries. Ann. Math 2(107), 371–384 (1978)CrossRefMathSciNetGoogle Scholar
- 13.Diederich, K., Pinchuk, S.: Reflection principle in higher dimensions. Doc. Math. 2, 703–712 (1998)MathSciNetGoogle Scholar
- 14.Diederich, K., Pinchuk, S.: Analytic sets extending the graphs of holomorphic mappings. J. Geom. Anal. 14(2), 231–239 (2004)CrossRefMathSciNetMATHGoogle Scholar
- 15.Diederich, K., Pinchuk, S.: Proper holomorphic maps in dimension 2 extend. Indiana Univ. Math. J. 44, 1089–1126 (1995)CrossRefMathSciNetMATHGoogle Scholar
- 16.Diederich, K., Pinchuk, S.: Regularity of continuous CR maps in arbitrary dimension. Michigan Math. J. 51(1), 111–140 (2003)CrossRefMathSciNetMATHGoogle Scholar
- 17.Diederich, K., Pinchuk, S.: The geometric reflection principle in several complex variables. Complex Var. Elliptic Equ. 54(3–4), 223–224 (2009)CrossRefMathSciNetMATHGoogle Scholar
- 18.Diederich, K., Webster, S.M.: A reflection principle for degenerate real hypersurfaces. Duke Math. J. 47, 835–843 (1980)CrossRefMathSciNetMATHGoogle Scholar
- 19.Forstnerič, F.: Extending proper holomorphic mappings of positive codimension. Invent. Math. 95, 31–62 (1989)CrossRefMathSciNetMATHGoogle Scholar
- 20.Forstnerič, F.: A survey on proper holomorphic mappings, Proceeding of Year in SCVs at Mittag-Leffler Institute, Math. Notes 38, Princeton, N. J., Princeton University Press, (1992)Google Scholar
- 21.Han, C.K.: Analyticity of CR equivalences between some real hypersurfaces in \({\mathbb{C}}^n\) with degenerate Levi forms. Invent. Math. 73, 51–69 (1983)CrossRefMathSciNetMATHGoogle Scholar
- 22.Huang, X.: On the mapping problem for algebraic real hypersurfaces in the complex spaces of different dimensions. Ann. Inst. Fourier (Grenoble) 44(2), 433–463 (1994)CrossRefMathSciNetMATHGoogle Scholar
- 23.Huang, X.: On some problems in several complex variables and CR geometry, First International Congress of Chinese Mathematicians (Beijing, 1998), eds. L. Yang, S.-T. Yau. AMS/IP Stud. Adv. Math. Vol. 20, pp. 383–396. Providence, RI: American Mathematical Society (2001)Google Scholar
- 24.Huang, X.: A removable singularity property for CR mappings between real-analytic hypersurfaces. Comm. Partial Differ. Equ. 25, 299–317 (2000)CrossRefMATHGoogle Scholar
- 25.Lewy, H.: On the boundary behaviour of holomorphic mappings. Accad. Naz. Lincei 35, 1–8 (1977)Google Scholar
- 26.Merker, J., Meylan, F.: On the Schwarz symmetry principle in a model case. Proc. Amer. Math. Soc. 127, 1097–1102 (1999)CrossRefMathSciNetMATHGoogle Scholar
- 27.Meylan, F., Mir, N., Zaitsev, D.: Holomorphic extension of smooth CR-mappings between real-analytic and real-algebraic CR-manifolds. Asian J. Math. 7(4), 493–509 (2003)MathSciNetMATHGoogle Scholar
- 28.Pinchuk, S.: On the analytic continuation of holomorphic mappings. Mat. Sb. 27, 345–392 (1975)Google Scholar
- 29.Pinchuk, S.: Analytic Continuation of Holomorphic Mappings and the Problem of Holomorphic Classification of Multidimensional Domains, Doctoral Dissertation. Moscow State Univ, Habilitation (1980)Google Scholar
- 30.Pinchuk, S.: Bogoljubovs theorem on the edge of the wedge for generic manifolds. Math. USSR Sbornik 23, 441–455 (1974)CrossRefGoogle Scholar
- 31.Pinchuk, S., Sukhov, A.: Extension of CR maps of positive codimension. Proc. Steklov Inst. Math. 253(2), 246–255 (2006)CrossRefMathSciNetGoogle Scholar
- 32.Pinchuk, S., Verma, K.: Analytic sets and the boundary regularity of CR mappings. Proc. Amer. Math. Soc. 129(9), 2623–2632 (2001)CrossRefMathSciNetMATHGoogle Scholar
- 33.Shafikov, R., Verma, K.: Extension of holomorphic maps between real hypersurfaces of different dimensions. Ann. Inst. Fourier (Grenoble) 57(6), 2063–2080 (2007)CrossRefMathSciNetMATHGoogle Scholar
- 34.Trepreau, J.M.: Sur le prolongement holomorphe des fonctions CR définies sur une hypersurface réelle de classe \({\cal {C}}^2\) dans \({\mathbb{C}}^{n}\). Invent. Math. 83, 583–592 (1986)CrossRefMathSciNetMATHGoogle Scholar
- 35.Vladimirov, V.S.: Methods of the theory of functions of many complex variables, p. 1551. Mit Press MR, Cambridge, MA (1966)Google Scholar
- 36.Webster, S.: On the mapping problem for algebraic real hypersurfaces. Invent. Math. 43, 53–68 (1977)CrossRefMathSciNetMATHGoogle Scholar
- 37.Zaitsev, D.: Algebraicity of local holomorphisms between real-algebraic submanifolds of complex spaces. Acta Math. 183(2), 273–305 (1999)CrossRefMathSciNetMATHGoogle Scholar