Waldemar Pompe
(2003)
If is a bounded domain with Lipschitz boundary and is an open subset of , we prove that the following inequality
holds for all and , where
defines an elliptic differential operator of first order with continuous coefficients on . As a special case we obtain
for all vanishing on , where is a continuous mapping with . Next we show that is not valid if , and , but does hold if , and is symmetric and positive definite in .