{ "id": "2103.11482", "version": "v1", "published": "2021-03-21T20:46:01.000Z", "updated": "2021-03-21T20:46:01.000Z", "title": "Heat kernel bounds for parabolic equations with singular (form-bounded) vector fields", "authors": [ "D. Kinzebulatov", "Yu. A. Semenov" ], "categories": [ "math.AP", "math.PR" ], "abstract": "We consider Kolmogorov operator $-\\nabla \\cdot a \\cdot \\nabla + b \\cdot \\nabla$ with measurable uniformly elliptic matrix $a$ and prove Gaussian lower and upper bounds on its heat kernel under minimal assumptions on the vector field $b$ and divergence ${\\rm div\\,}b$. More precisely, we prove: (1) Gaussian lower bound, provided that ${\\rm div\\,}b \\geq 0$, and $b$ is in the class of form-bounded vector fields (containing e.g.\\,the class $L^d$, the weak $L^d$ class, as well as some vector fields that are not even in $L_{\\rm loc}^{2+\\varepsilon}$, $\\varepsilon>0$); in these assumptions, the Gaussian upper bound is in general invalid; (2) Gaussian upper and lower bounds, provided that $b$ is form-bounded, ${\\rm div\\,}b$ is in the Kato class.", "revisions": [ { "version": "v1", "updated": "2021-03-21T20:46:01.000Z" } ], "analyses": { "keywords": [ "vector field", "heat kernel bounds", "parabolic equations", "gaussian lower bound", "gaussian upper bound" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }