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Geometric second derivative estimates in Carnot groups and convexity

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Abstract

We prove some new a priori estimates for H 2-convex functions which are zero on the boundary of a bounded smooth domain Ω in a Carnot group \({\mathbb{G}}\) . Such estimates are global and are geometric in nature as they involve the horizontal mean curvature \({\mathcal{H}}\) of ∂Ω. As a consequence of our bounds we show that if \({\mathbb{G}}\) has step two, then for any smooth H 2-convex function in \(\Omega \subset {\mathbb{G}}\) vanishing on ∂Ω one has

$$\sum \limits _{i,j=1} ^m \int \limits_\Omega ([X_i,X_j]u)^2 \, dg \, \leq \, \frac{4}{3} \int \limits_{\partial \Omega} \mathcal H\ |\nabla_H u|^2\, d\sigma_H$$

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References

  1. Balogh Z.M. (2003). Size of characteristic sets and functions with prescribed gradients. J. Reine Angew. Math. 564: 63–83

    MathSciNet  MATH  Google Scholar 

  2. Bernstein S.N. (1906). Sur la généralisation du probléme de Dirichlet, I. Math. Ann. 62: 253–271

    Article  MathSciNet  MATH  Google Scholar 

  3. Bernstein S.N. (1910). Sur la généralisation du probléme de Dirichlet, II. Math. Ann. 69: 82–136

    Article  MathSciNet  MATH  Google Scholar 

  4. Bieske T. (2002). On ∞-harmonic functions on the Heisenberg group. Commun. Part. Differ. Equ. 27(3–4): 727–761

    Article  MathSciNet  MATH  Google Scholar 

  5. Bieske T. and Capogna L. (2005). The Aronsson–Euler equation for absolutely minimizing Lipschitz extensions with respect to Carnot-Carathéodory metrics. Trans. Am. Math. Soc. 357(2): 795–823

    Article  MathSciNet  MATH  Google Scholar 

  6. Bony J.M. (1969). Principe du maximum, inégalité de Harnack et unicité du problème de Cauchy pour les operateurs elliptique degeneres. Ann. Inst. Fourier Grenoble, 1 119: 277–304

    MathSciNet  Google Scholar 

  7. Bony J.M. (1994). The geometric Sobolev embedding for vector fields and the isoperimetric inequality, Comm. Anal. Geom. 2(2): 203–215

    MathSciNet  Google Scholar 

  8. Chanillo, S., Manfredi, J.: Sharp global bounds for the Hessian on pseudo-Hermitian manifolds (preprint) (2007)

  9. Danielli, D., Garofalo, N.: Geometric properties of solutions to subelliptic equations in nilpotent Lie groups. In: Caristi Invernizzi,G., Mitidieri E. (eds) Lecture Notes in Pure and Applied Mathematics, “Reaction Diffusion Systems”, Trieste, vol 194. Marcel Dekker, New York (1998)

  10. Danielli D., Garofalo N. and Nhieu D.M. (2003). Notions of convexity in Carnot groups. Commun. Anal. Geom. 11(2): 263–341

    MathSciNet  MATH  Google Scholar 

  11. Danielli D., Garofalo N. and Nhieu D.M. (2007). Sub-Riemannian calculus on hypersurfaces in Carnot groups. Adv. Math. 215(1): 292–378

    Article  MathSciNet  MATH  Google Scholar 

  12. Danielli D., Garofalo N., Nhieu D.M. and Tournier F. (2004). The theorem of Busemann–Feller–Alexandrov in Carnot groups. Commun. Anal. Geom. 12(4): 853–886

    MathSciNet  MATH  Google Scholar 

  13. Domokos A. and Manfredi J.J. (2005). Subelliptic Cordes estimates. Proc. Am. Math. Soc. 133(4): 1047–1056

    Article  MathSciNet  MATH  Google Scholar 

  14. Folland G.B. (1975). Subelliptic estimates and function spaces on nilpotent Lie groups. Ark. Math. 13: 161–207

    Article  MathSciNet  MATH  Google Scholar 

  15. Garofalo N. and Tournier F. (2006). New properties of convex functions in the Heisenberg group. Trans. Am. Math. Soc. 358(5): 2011–2055

    Article  MathSciNet  MATH  Google Scholar 

  16. Garofalo N. and Vassilev D.N. (2000). Regularity near the characteristic set in the non-linear Dirichlet problem and conformal geometry of sub-Laplacians on Carnot groups. Math. Ann. 318: 453–516

    Article  MathSciNet  MATH  Google Scholar 

  17. Greenleaf A. (1985). The first eigenvalue of a sub-Laplacian on a pseudo-Hermitian manifold. Commun. Part. Differ. Equ. 10(2): 191–217

    Article  MathSciNet  MATH  Google Scholar 

  18. Grisvard P. (1985). Elliptic Problems in Nonsmooth Domains, Monographs and Studies in Mathematics, vol. 24. Pitman (Advanced Publishing Program), Boston

    Google Scholar 

  19. Gutierrez C. and Montanari A.M. (2004). Maximum and comparison principles for convex functions on the Heisenberg group. Commun. Part. Differ. Equ. 29(9–10): 1305–1334

    Article  MathSciNet  MATH  Google Scholar 

  20. Gutierrez C. and Montanari A.M. (2004). On the second order derivatives of convex functions on the Heisenberg group. Ann. Sc. Norm. Super. Pisa Cl. Sci. (5) 3(2): 349–366

    MathSciNet  MATH  Google Scholar 

  21. Hladky, R.K., Pauls, S.D.: Constant mean curvature surfaces in sub-Riemannian geometry (2005, preprint)

  22. Hörmander H. (1967). Hypoelliptic second-order differential equations. Acta Math. 119: 147–171

    Article  MathSciNet  MATH  Google Scholar 

  23. Kadlec J. (1964). The regularity of the solution of the Poisson problem in a domain whose boundary is similar to that of a convex domain. Czechoslov. Math. J. 14(89): 386–393

    MathSciNet  Google Scholar 

  24. Kohn J.J. (1973). Pseudo-differential operators and hypoellipticity. Proc. Symp. Pure Math. 23: 61–69

    MathSciNet  Google Scholar 

  25. Lewis J.E. (1978). Estimates for Poisson’s equation when the curvature of the boundary is in an Orlicz class. Boll. Un. Math. Ital. A (5) 15(1): 87–93

    MATH  Google Scholar 

  26. Ladyzhenskaya O.A. and Ural’tseva N.N. (1968). Linear and Quasilinear Elliptic Equations. Academic Press, London

    MATH  Google Scholar 

  27. Lu G., Manfredi J. and Stroffolini B. (2004). Convex functions on the Heisenberg group. Calc. Var. Part. Differ. Equ. 19(1): 1–22

    Article  MathSciNet  Google Scholar 

  28. Magnani V. (2006). Characteristic points, rectifiability and perimeter measure on stratified groups. J. Eur. Math. Soc. (JEMS) 8(4): 585–609

    Article  MathSciNet  MATH  Google Scholar 

  29. Rickly M. (2006). First-order regularity of convex functions on Carnot groups. J. Geom. Anal. 16(4): 679–702

    MathSciNet  MATH  Google Scholar 

  30. Stein E.M. (1993). Harmonic Analysis: Real Variable Methods, Orthogonality and Oscillatory Integrals. Princeton University Press, Princeton

    MATH  Google Scholar 

  31. Strichartz R.S. (1991). L p harmonic analysis and Radon transforms on the Heisenberg group. J. Funct. Anal. 96: 350–406

    Article  MathSciNet  MATH  Google Scholar 

  32. Talenti G. (1965). Sopra una classe di equazioni ellittiche a coefficienti misurabili. Ann. Mat. Pura Appl. 69: 285–304

    Article  MathSciNet  MATH  Google Scholar 

  33. Wang C. The comparison principle for viscosity solutions of fully nonlinear sub-elliptic equations in Carnot groups (2003, preprint)

  34. Wang C. (2005). Viscosity convex functions on Carnot groups. Proc. Am. Math. Soc. 133(4): 1247–1253

    Article  MATH  Google Scholar 

  35. Wang C. (2007). The Aronsson equation for absolute minimizers of L -functionals associated with vector fields satisfying Hörmander’s condition. Trans. Am. Math. Soc. 359(1): 91–113

    Article  MATH  Google Scholar 

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Correspondence to Nicola Garofalo.

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Supported in part by NSF Grant DMS-07010001.

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Garofalo, N. Geometric second derivative estimates in Carnot groups and convexity. manuscripta math. 126, 353–373 (2008). https://doi.org/10.1007/s00229-008-0182-y

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