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The traveling salesman problem in the Heisenberg group: upper bounding curvature. (English) Zbl 1350.53044

Summary: We show that if a subset \( K\) in the Heisenberg group (endowed with the Carnot-Carathéodory metric) is contained in a rectifiable curve, then it satisfies a modified analogue of Peter Jones’s geometric lemma. This is a quantitative version of the statement that a finite length curve has a tangent at almost every point. This condition complements that of a work by F. Ferrari et al. [Rev. Mat. Iberoam. 23, No. 2, 437–480 (2007; Zbl 1142.28004)] except a power 2 is changed to a power 4. Two key tools that we use in the proof are a geometric martingale argument like that of the second author [J. Anal. Math. 103, 331–375 (2007; Zbl 1152.28006)] as well as a new curvature inequality in the Heisenberg group.

MSC:

53C17 Sub-Riemannian geometry
28A75 Length, area, volume, other geometric measure theory

References:

[1] Bishop, Christopher J.; Jones, Peter W., Harmonic measure, \(L^2\) estimates and the Schwarzian derivative, J. Anal. Math., 62, 77-113 (1994) · Zbl 0801.30024 · doi:10.1007/BF02835949
[2] Christ, Michael, A \(T(b)\) theorem with remarks on analytic capacity and the Cauchy integral, Colloq. Math., 60/61, 2, 601-628 (1990) · Zbl 0758.42009
[3] Cygan, Jacek, Subadditivity of homogeneous norms on certain nilpotent Lie groups, Proc. Amer. Math. Soc., 83, 1, 69-70 (1981) · Zbl 0475.43010 · doi:10.2307/2043893
[4] David, Guy, Wavelets and singular integrals on curves and surfaces, Lecture Notes in Mathematics 1465, x+107 pp. (1991), Springer-Verlag, Berlin · Zbl 0764.42019 · doi:10.1007/BFb0091544
[5] David, G.; Semmes, S., Singular integrals and rectifiable sets in \(\mathbb{R}^n\): beyond Lipschitz graphs, Ast\'erique, 193 (1991) · Zbl 0743.49018
[6] David, Guy; Semmes, Stephen, Analysis of and on uniformly rectifiable sets, Mathematical Surveys and Monographs 38, xii+356 pp. (1993), American Mathematical Society, Providence, RI · Zbl 0832.42008 · doi:10.1090/surv/038
[7] Ferrari, Fausto; Franchi, Bruno; Pajot, Herv{\'e}, The geometric traveling salesman problem in the Heisenberg group, Rev. Mat. Iberoam., 23, 2, 437-480 (2007) · Zbl 1142.28004 · doi:10.4171/RMI/502
[8] Hahlomaa, Immo, Menger curvature and Lipschitz parametrizations in metric spaces, Fund. Math., 185, 2, 143-169 (2005) · Zbl 1077.54016 · doi:10.4064/fm185-2-3
[9] Hahlomaa, Immo, Curvature integral and Lipschitz parametrization in 1-regular metric spaces, Ann. Acad. Sci. Fenn. Math., 32, 1, 99-123 (2007) · Zbl 1117.28001
[10] Jones, Peter W., Rectifiable sets and the traveling salesman problem, Invent. Math., 102, 1, 1-15 (1990) · Zbl 0731.30018 · doi:10.1007/BF01233418
[11] Juillet, Nicolas, A counterexample for the geometric traveling salesman problem in the Heisenberg group, Rev. Mat. Iberoam., 26, 3, 1035-1056 (2010) · Zbl 1206.28003 · doi:10.4171/RMI/626
[12] Li, Sean, Coarse differentiation and quantitative nonembeddability for Carnot groups, J. Funct. Anal., 266, 7, 4616-4704 (2014) · Zbl 1311.46021 · doi:10.1016/j.jfa.2014.01.026
[13] Li, S., Markov convexity and nonembeddability of the Heisenberg group (2014)
[14] Li, S.; Schul, R., An upper bound for the length of a Traveling Salesman path in the Heisenberg group (2014)
[15] Montgomery, Richard, A tour of subriemannian geometries, their geodesics and applications, Mathematical Surveys and Monographs 91, xx+259 pp. (2002), American Mathematical Society, Providence, RI · Zbl 1044.53022
[16] Okikiolu, Kate, Characterization of subsets of rectifiable curves in \({\bf R}^n\), J. London Math. Soc. (2), 46, 2, 336-348 (1992) · Zbl 0758.57020 · doi:10.1112/jlms/s2-46.2.336
[17] Pajot, Herv{\'e}, Analytic capacity, rectifiability, Menger curvature and the Cauchy integral, Lecture Notes in Mathematics 1799, xii+119 pp. (2002), Springer-Verlag, Berlin · Zbl 1043.28002 · doi:10.1007/b84244
[18] Schul, Raanan, Ahlfors-regular curves in metric spaces, Ann. Acad. Sci. Fenn. Math., 32, 2, 437-460 (2007) · Zbl 1122.28006
[19] Schul, Raanan, Subsets of rectifiable curves in Hilbert space-the analyst’s TSP, J. Anal. Math., 103, 331-375 (2007) · Zbl 1152.28006 · doi:10.1007/s11854-008-0011-y
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