1 3 Ja n 20 06 Positivity and strong ellipticity
نویسندگان
چکیده
We consider partial differential operators H = − div(C∇) in divergence form on R with a positive-semidefinite, symmetric, matrix C of real L∞-coefficients and establish that H is strongly elliptic if and only if the associated semigroup kernel satisfies local lower bounds, or, if and only if the kernel satisfies Gaussian upper and lower bounds.
منابع مشابه
ar X iv : m at h / 06 01 74 3 v 1 [ m at h . SP ] 3 0 Ja n 20 06 DETERMINANTS OF ZEROTH ORDER OPERATORS
متن کامل
m at h . FA ] 3 1 Ja n 20 06 A HEREDITARILY INDECOMPOSABLE ASYMPTOTIC l 2 BANACH SPACE
A Hereditarily Indecomposable asymptotic ℓ 2 Banach space is constructed. The existence of such a space answers a question of B. Maurey and verifies a conjecture of W.T. Gowers.
متن کامل