2009/01/21 by E. Durand, Durand, E., J. A. Jaramillo +1
Mathematics · #46E15 #46E35 #FOS: Mathematics #Metric Geometry (math.MG) #math.MG #msc:46E15 #msc:46E35
paper · pdf · doi:10.48550/arxiv.0901.3236
28 pages, 2 figures
arxiv created 2009/01/21 · arxiv updated 2009/12/01
For a metric space X, we study the space D∞(X) of bounded functions on X whose infinitesimal Lipschitz constant is uniformly bounded. D∞(X) is compared with the space \LIP∞(X) of bounded Lipschitz functions on X, in terms of different properties regarding the geometry of X. We also obtain a Banach-Stone theorem in this context. In the case of a metric measure space, we also compare D∞(X) with the Newtonian-Sobolev space N1, ∞(X). In particular, if X supports a doubling measure and satisfies a local Poincaré inequality, we obtain that D∞(X)=N1, ∞(X).