TY - JOUR T1 - A Nash Type Result for Divergence Parabolic Equation Related to Hörmander's Vector Fields AU - Hou , Lingling AU - Niu , Pengcheng JO - Journal of Partial Differential Equations VL - 4 SP - 341 EP - 376 PY - 2020 DA - 2020/08 SN - 33 DO - http://doi.org/10.4208/jpde.v33.n4.3 UR - https://global-sci.org/intro/article_detail/jpde/17863.html KW - Hörmander's vector fields, divergence parabolic equation, weak solution, Hölder regularity, Harnack inequality. AB -
In this paper we consider the divergence parabolic equation with bounded and measurable coefficients related to Hörmander's vector fields and establish a Nash type result, i.e., the local Hölder regularity for weak solutions. After deriving the parabolic Sobolev inequality, (1,1) type Poincaré inequality of Hörmander's vector fields and a De Giorgi type Lemma, the Hölder regularity of weak solutions to the equation is proved based on the estimates of oscillations of solutions and the isomorphism between parabolic Campanato space and parabolic Hölder space. As a consequence, we give the Harnack inequality of weak solutions by showing an extension property of positivity for functions in the De Giorgi class.