2016/03/09 by Nicola Garofalo, Garofalo, Nicola, Isidro H. Munive +1
Mathematics · #Analysis of PDEs (math.AP) #FOS: Mathematics #math.AP
paper · pdf · doi:10.48550/arxiv.1603.02988
arXiv admin note: text overlap with arXiv:0803.0784
arxiv created 2016/03/09 · arxiv updated 2016/03/10
In a cylinder DT = Ω× (0,T), where Ω⊂ ℝn, we examine the relation between the L-caloric measure, dω(x,t), where L is the heat operator associated with a system of vector fields of Hörmander type, and the measure dσX× dt, where dσX is the intrinsic X-perimeter measure. The latter constitutes the appropriate replacement for the standard surface measure on the boundary and plays a central role in sub-Riemannian geometric measure theory. Under suitable assumptions on the domain Ω we establish the mutual absolute continuity of dω(x,t) and dσX× dt. We also derive the solvability of the initial-Dirichlet problem for L with boundary data in appropriate Lp spaces, for every p>1.