Elliptic differential operator
= Elliptic differential operator
{wiki}
A constant-coefficient operator of order $N$ is elliptic when its homogeneous principal symbol $P_N(\xi)$ is nonzero for every real $\xi\ne0$.
= Elliptic differential operator
{wiki}
A constant-coefficient operator of order $N$ is elliptic when its homogeneous principal symbol $P_N(\xi)$ is nonzero for every real $\xi\ne0$.