Abstract
In this paper, we provide a different approach to the Alt–Caffarelli–Friedman monotonicity formula, reducing the problem to test the monotone increasing behavior of the mean value of a function involving the gradient’s norm. In particular, we show that our argument holds in the general framework of Carnot groups.
Similar content being viewed by others
References
Alt, H.W., Caffarelli, L.A., Friedman, A.: Variational problems with two phases and their free boundaries. Trans. Am. Math. Soc. 282(2), 431–461 (1984)
Bonfiglioli, A., Lanconelli, E., Uguzzoni, F.: Springer Monographs in Mathematics. Stratified Lie groups and potential theory for their sub-Laplacians, Springer, Berlin (2007)
Caffarelli, L., Salsa, S.: A geometric approach to free boundary problems. In: Graduate Studies in Mathematics, vol. 68. American Mathematical Society, Providence (2005)
Citti, G., Garofalo, N., Lanconelli, E.: Harnack’s inequality for sum of squares of vector fields plus a potential. Am. J. Math. 115(3), 699–734 (1993)
Fabes, E.B., Garofalo, N.: Mean value properties of solutions to parabolic equations with variable coefficients. J. Math. Anal. Appl. 121(2), 305–316 (1987)
Ferrari, F., Forcillo, N.: A counterexample to the monotone increasing behavior of an Alt Caffarelli–Friedman formula in the Heisenberg group. In: Rendiconti Lincei Matematica e Applicazioni. arXiv:2203.06232v1 (press)
Ferrari, F., Forcillo, N.: A new glance to the Alt–Caffarelli–Friedman monotonicity formula. Math. Eng. 2(4), 657–679 (2020)
Ferrari, F., Lederman, C., Salsa, S.: Recent results on nonlinear elliptic free boundary problems. Vietnam J. Math. 50(4), 977–996 (2022)
Folland, G.B., Stein, E.M.: Hardy spaces on homogeneous groups. In: Mathematical Notes, vol. 28. Princeton University Press, Princeton. University of Tokyo Press, Tokyo (1982)
Franchi, B., Serapioni, R., Serra Cassano, F.: Meyers–Serrin type theorems and relaxation of variational integrals depending on vector fields. Houston J. Math. 22(4), 859–890 (1996)
Franchi, B., Serapioni, R., Serra Cassano, F.: On the structure of finite perimeter sets in step 2 Carnot groups. J. Geom. Anal. 13(3), 421–466 (2003)
Fulks, W.: A mean value theorem for the heat equation. Proc. Am. Math. Soc. 17, 6–11 (1966)
Garofalo, N.: A note on monotonicity and Bochner formulas in Carnot groups. Proc. R. Soc. Edinb. Sect. B Math. 2, 1–21 (2022)
Garofalo, N., Nhieu, D.-M.: Isoperimetric and Sobolev inequalities for Carnot–Carathéodory spaces and the existence of minimal surfaces. Commun. Pure Appl. Math. 49(10), 1081–1144 (1996)
Gilbarg, D., Trudinger, N.S.: Elliptic partial differential equations of second order. In: Classics in Mathematics. Springer, Berlin (reprint of the 1998 edition) (2001)
Hörmander, L.: Hypoelliptic second order differential equations. Acta Math. 119, 147–171 (1967)
Kupcov, L.P.: A mean value theorem and a maximum principle for a Kolmogorov equation. Mat. Zametki 15, 479–489 (1974)
Kupcov, L.P.: The mean value property and the maximum principle for second order parabolic equations. Dokl. Akad. Nauk SSSR 242(3), 529–532 (1978)
Kupcov, L.P.: On parabolic means. Dokl. Akad. Nauk SSSR 252(2), 296–301 (1980)
Kuptsov, L.P.: Property of the mean for the generalized equation of A. N. Kolmogorov I. Differ. Uravneniya 19(2), 295–304 (1983). (366-367)
Netuka, I., Veselý, J.: Mean value property and harmonic functions. In: Classical and modern potential theory and applications (Chateau de Bonas, 1993). NATO Advanced Science Institute Series C: Mathematics Physics Science, vol. 430, pp. 359–398. Kluwer Academic Publication, Dordrecht (1994)
Pini, B.: Maggioranti e minoranti delle soluzioni delle equazioni paraboliche. Ann. Mat. Pura Appl. 4(37), 249–264 (1954)
Pini, B.: Sulla soluzione generalizzata di Wiener per il primo problema di valori al contorno nel caso parabolico. Rend. Sem. Mat. Univ. Padova 23, 422–434 (1954)
Stein, E.M.: Harmonic analysis: real-variable methods, orthogonality, and oscillatory integrals. In: Princeton Mathematical Series, vol. 43. Princeton University Press, Princeton (with the assistance of Timothy S. Murphy, monographs in harmonic analysis, III) (1993)
Weber, M.: The fundamental solution of a degenerate partial differential equation of parabolic type. Trans. Am. Math. Soc. 71, 24–37 (1951)
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
On behalf of all authors, the corresponding author states that there is no conflict of interest.
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Fausto Ferrari and Nicolò Forcillo are partially supported by INDAM-GNAMPA-2019 project: Proprietà di regolarità delle soluzioni viscose con applicazioni a problemi di frontiera libera.
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Ferrari, F., Forcillo, N. Alt–Caffarelli–Friedman monotonicity formula and mean value properties in Carnot groups with applications. Boll Unione Mat Ital (2023). https://doi.org/10.1007/s40574-023-00393-5
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s40574-023-00393-5