Using the exact representation of Carnot-Carathéodory balls in the Heisenberg group, we prove that: 1. in the classical sense for all with , where is the distance from the origin; 2. Metric balls are not optimal isoperimetric sets in the Heisenberg group.
Usando la rappresentazione esatta per le sfere di Carnot-Carath´ eodory nel gruppo di Heisenberg, proviamo che: 1. in senso classico per ogni con , dove è la distanza dall’origine; 2. Le sfere metriche non sono insiemi isoperimetrici ottimali nel gruppo di Heisenberg.
@article{RLIN_2000_9_11_3_155_0, author = {Roberto Monti}, title = {Some properties of Carnot-Carath\'eodory balls in the Heisenberg group}, journal = {Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni}, volume = {11}, year = {2000}, pages = {155-167}, zbl = {1197.53064}, mrnumber = {1841689}, language = {en}, url = {http://dml.mathdoc.fr/item/RLIN_2000_9_11_3_155_0} }
Monti, Roberto. Some properties of Carnot-Carathéodory balls in the Heisenberg group. Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni, Tome 11 (2000) pp. 155-167. http://gdmltest.u-ga.fr/item/RLIN_2000_9_11_3_155_0/
[1] | MR 1325922 | Zbl 0819.49002
, Mathematical methods in optimization of differential systems. Kluwer, Dordrecht1994.[2] The tangent space in subriemannian geometry. In: - (eds), Sub-Riemannian Geometry. Progress in Mathematics, 144, Birkhäuser, Basel 1996. | Zbl 0862.53031
,[3] Some results in surface measure in Calculus of Variations. Ann. Mat. Pura Appl., (4), 170, 1996, 329-357. | MR 1441625 | Zbl 0890.49020
- - ,[4] Control theory and singular Riemannian geometry. In: - , New directions in applied mathematics. Springer-Verlag, New York 1981. | MR 661282 | Zbl 0483.49035
,[5] | MR 936419 | Zbl 0633.53002
- , Geometric inequalities. Springer-Verlag, Berlin 1988.[6] Sulla proprietà isoperimetrica dell’ipersfera, nella classe degli insiemi aventi frontiera orientata di misura finita. Atti Acc. Lincei Mem. fis., s. 8, v. 5, 1958, 33-44. | MR 98331 | Zbl 0116.07901
,[7] | MR 657581 | Zbl 0508.42025
- , Hardy spaces on homogeneous groups. Princeton University Press, 1982.[8] Stime subellittiche e metriche riemanniane singolari II. Seminario di Analisi Matematica, Università di Bologna, 1983, VIII-1 VIII-17.
,[9] Sobolev and isoperimetric inequalities for degenerate metrics. Math. Ann., 300, 1994, 557-571. | MR 1314734 | Zbl 0830.46027
- - ,[10] Meyers-Serrin Type Theorems and Relaxation of Variational Integrals Depending Vector Fields. Houston Journal of Mathematics, 22, 4, 1996, 859-889. | MR 1437714 | Zbl 0876.49014
- - ,[11] Approximation and Imbedding Theorems for Weighted Sobolev Spaces Associated with Lipschitz Continuous Vector Fields. Bollettino U.M.I., 7, 11-B, 1997, 83-117. | MR 1448000 | Zbl 0952.49010
- - ,[12] Rectifiability and perimeter in the Heisenberg group. Preprint 2000. | MR 1871966 | Zbl 1057.49032
- - ,[13] Isoperimetric and Sobolev inequalities for Carnot-Carathéodory spaces and the existence of minimal surfaces. Comm. Pure Appl. Math., 49, 1996, 1081-1144. | MR 1404326 | Zbl 0880.35032
- ,[14] Lipschitz continuity, global smooth approximations and extension theorems for Sobolev functions in Carnot Carathéodory spaces. Jour. Analyse Mathematique, 74, 1998, 67-97. | MR 1631642 | Zbl 0906.46026
- ,[15] Principe de moindre action, propagation de la chaleur et estimées sous elliptiques sur certains groupes nilpotents. Acta Math., 139, 1977, 1-2, 95-153. | MR 461589 | Zbl 0366.22010
,[16] Carnot-Carathéodory spaces seen from within. In: - (eds.), Sub-Riemannian Geometry. Progress in Mathematics, 144, Birkhäuser, Basel 1996. | MR 1421823 | Zbl 0864.53025
,[17] | MR 682063 | Zbl 0509.53034
, Structures métriques pour les variétés riemanniennes. CEDIC, Paris1981.[18] Subelliptic, second order differential operators. In: Complex analysis III. Springer, 1987, 46-77. | MR 922334 | Zbl 0634.35017
- ,[19] Shortest paths for sub-Riemannian metrics on rank-two distributions. Mem. Amer. Math. Soc., 118, 1995. | MR 1303093 | Zbl 0843.53038
- ,[20] Abnormal minimizers. SIAM J. Control Optim., 32, 1994, 1605-1620. | MR 1297101 | Zbl 0816.49019
,[21] Surface measures in Carnot-Carathéodory spaces. Forthcoming. | Zbl 1032.49045
- ,[22] Une inégalité isopérimétrique sur le groupe de Heisenberg. C.R. Acad. Sci. Paris, 295, I, 1982, 127-130. | MR 676380 | Zbl 0502.53039
,[23] | MR 1232192 | Zbl 0821.42001
, Harmonic Analysis. Princeton University Press, 1993.[24] Sub-Riemannian geometry. J. Differential Geom., 24, 1986, 221-263.[Corrections to «Sub-Riemannian geometry». J. Differential Geom., 30, 1989, 595-596]. | MR 862049 | Zbl 0609.53021
,