Abstract
We prove that every Lipschitz function from a subset of a locally compact length space to a metric tree has a unique absolutely minimal Lipschitz extension (AMLE). We relate these extensions to a stochastic game called Politics—a generalization of a game called Tug of War that has been used in Peres et al. (J Am Math Soc 22(1):167–210, 2009) to study real-valued AMLEs.
Similar content being viewed by others
References
Almansa A., Cao F., Gousseau Y., Rouge B.: Interpolation of digital elevation models using AMLE and related methods. IEEE Trans. Geosci. Remote Sens. 40(2), 314–325 (2002)
Armstrong S.N., Smart C.K.: An easy proof of Jensen’s theorem on the uniqueness of infinity harmonic functions. Calc. Var. Partial Differ. Equ. 37(3–4), 381–384 (2010)
Aronsson G.: Extension of functions satisfying Lipschitz conditions. Ark. Mat. 6, 551–561 (1967)
Aronsson G., Crandall M.G., Juutinen P.: A tour of the theory of absolutely minimizing functions. Bull. Am. Math. Soc. (N.S.), 41(4), 439–505 (2004) (electronic)
Ball K.: Markov chains, Riesz transforms and Lipschitz maps. Geom. Funct. Anal. 2(2), 137–172 (1992)
Barles G., Busca J.: Existence and comparison results for fully nonlinear degenerate elliptic equations without zeroth-order term. Commun. Partial Differ. Equ. 26(11–12), 2323–2337 (2001)
Benyamini Y., Lindenstrauss J.: Geometric Nonlinear Functional Analysis, vol. 1. American Mathematical Society Colloquium Publications, vol. 48. American Mathematical Society, Providence (2000)
Brudnyi A., Brudnyi Y.: Linear and nonlinear extensions of Lipschitz functions from subsets of metric spaces. Algebra i Analiz 19(3), 106–118 (2007)
Brudnyi Y., Shvartsman P.: Stability of the Lipschitz extension property under metric transforms. Geom. Funct. Anal. 12(1), 73–79 (2002)
Caselles V., Haro G., Sapiro G., Verdera J.: On geometric variational models for inpainting surface holes. Comput. Vis. Image Underst. 111(3), 351–373 (2008)
Caselles V., Morel J.-M., Sbert C.: An axiomatic approach to image interpolation. IEEE Trans. Image Process. 7(3), 376–386 (1998)
Champion T., De Pascale L.: Principles of comparison with distance functions for absolute minimizers. J. Convex Anal. 14(3), 515–541 (2007)
Crandall M.G., Evans L.C., Gariepy R.F.: Optimal Lipschitz extensions and the infinity Laplacian. Calc. Var. Partial Differ. Equ. 13(2), 123–139 (2001)
Dress A.: Trees, tight extensions of metric spaces, and the cohomological dimension of certain groups: a note on combinatorial properties of metric spaces. Adv. Math. 53(3), 321–402 (1984)
Dress, A., Moulton, V., Terhalle, W.: T-theory: an overview. Eur. J. Combin. 17(2–3):161–175 (1996) [discrete metric spaces (Bielefeld, 1994)]
Isbell J.R.: Six theorems about injective metric spaces. Comment. Math. Helv. 39, 65–76 (1964)
Jensen R.: Uniqueness of Lipschitz extensions: minimizing the sup norm of the gradient. Arch. Ration. Mech. Anal. 123(1), 51–74 (1993)
Johnson, W.B., Lindenstrauss, J.: Extensions of Lipschitz mappings into a Hilbert space. In: Conference in Modern Analysis and Probability (New Haven, Conn., 1982). Contemporary Mathematics, vol. 26, pp. 189–206. American Mathematical Society, Providence (1984)
Johnson W.B., Lindenstrauss J., Preiss D., Schechtman G.: Lipschitz quotients from metric trees and from Banach spaces containing l 1. J. Funct. Anal. 194(2), 332–346 (2002)
Johnson W.B., Lindenstrauss J., Schechtman G.: Extensions of Lipschitz maps into Banach spaces. Israel J. Math. 54(2), 129–138 (1986)
Juutinen P.: Absolutely minimizing Lipschitz extensions on a metric space. Ann. Acad. Sci. Fenn. Math. 27(1), 57–67 (2002)
Kalton N.J.: Extending Lipschitz maps into \({\fancyscript{C}(K)}\) -spaces. Israel J. Math. 162, 275–315 (2007)
Khuê N.V., Nhu N.T.: Lipschitz extensions and Lipschitz retractions in metric spaces. Colloq. Math. 45(2), 245–250 (1981)
Kirszbraun M.D.: Über die zusammenziehenden und Lipschitzchen Transformationen. Fundam. Math. 22, 77–108 (1934)
Lang U., Pavlović B., Schroeder V.: Extensions of Lipschitz maps into Hadamard spaces. Geom. Funct. Anal. 10(6), 1527–1553 (2000)
Lang U., Schlichenmaier T.: Nagata dimension, quasisymmetric embeddings, and Lipschitz extensions. Int. Math. Res. Not. (58), 3625–3655 (2005)
Lang U., Schroeder V.: Kirszbraun’s theorem and metric spaces of bounded curvature. Geom. Funct. Anal. 7(3), 535–560 (1997)
Lazarus A.J., Loeb D.E., Propp J.G., Stromquist W.R., Ullman D.H.: Combinatorial games under auction play. Games Econ. Behav. 27(2), 229–264 (1999)
Le Gruyer E.: On absolutely minimizing Lipschitz extensions and PDE Δ∞(u) = 0. NoDEA Nonlinear Differ. Equ. Appl. 14(1–2), 29–55 (2007)
Lee J.R., Naor A.: Extending Lipschitz functions via random metric partitions. Invent. Math. 160(1), 59–95 (2005)
Lindenstrauss J.: On nonlinear projections in Banach spaces. Mich. Math. J. 11, 263–287 (1964)
Marcus M.B., Pisier G.: Characterizations of almost surely continuous p-stable random Fourier series and strongly stationary processes. Acta Math. 152(3–4), 245–301 (1984)
Martin D.A.: The determinacy of Blackwell games. J. Symb. Log. 63(4), 1565–1581 (1998)
McShane E.J.: Extension of range of functions. Bull. Am. Math. Soc. 40(12), 837–842 (1934)
Mémoli, F., Sapiro, G., Thompson, P.: Geometric surface and brain warping via geodesic minimizing Lipschitz extensions. In: MFCA-2006 International Workshop on Mathematical Foundations of Computational Anatomy (MICCAI), pp. 58–67 (2006)
Mendel M., Naor A.: Some applications of Ball’s extension theorem. Proc. Am. Math. Soc. 134(9), 2577–2584 (2006) (electronic)
Mil’man V.A.: Absolutely minimal extensions of functions on metric spaces. Mat. Sb. 190(6), 83–110 (1999)
Munkres J.R.: Topology: a First Course. Prentice-Hall, Englewood Cliffs (1975)
Naor A.: A phase transition phenomenon between the isometric and isomorphic extension problems for Hölder functions between L p spaces. Mathematika 48(1–2), 253–271 (2001)
Naor A., Peres Y., Schramm O., Sheffield S.: Markov chains in smooth Banach spaces and Gromov-hyperbolic metric spaces. Duke Math. J. 134(1), 165–197 (2006)
Neyman, A., Sorin, S. (eds): Stochastic Games and Applications. NATO Science Series C: Mathematical and Physical Sciences, vol. 570. Kluwer, Dordrecht (2003)
Peres Y., Schramm O., Sheffield S., Wilson D.B.: Tug-of-war and the infinity Laplacian. J. Am. Math. Soc. 22(1), 167–210 (2009)
Przesławski K., Yost D.: Lipschitz retracts, selectors, and extensions. Mich. Math. J. 42(3), 555–571 (1995)
Sheffield, S., Smart, C.: Vector-valued optimal Lipschitz extensions. Preprint (2010)
Valentine F.A.: Contractions in non-Euclidean spaces. Bull. Am. Math. Soc. 50, 710–713 (1944)
Valentine F.A.: A Lipschitz condition preserving extension for a vector function. Am. J. Math. 67, 83–93 (1945)
Wells, J.H., Williams, L.R.: Embeddings and Extensions in Analysis. Springer, New York (1975) (Ergebnisse der Mathematik und ihrer Grenzgebiete, Band 84)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Naor, A., Sheffield, S. Absolutely minimal Lipschitz extension of tree-valued mappings. Math. Ann. 354, 1049–1078 (2012). https://doi.org/10.1007/s00208-011-0753-1
Received:
Revised:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00208-011-0753-1