On elliptic operators in
Robert C. McOwen · Communications in Partial Differential Equations · 1980
In this paper we study the normal solvability of elliptic systems of partial differential operators on weighted n Sobolev spaces in R . The operators are particularly simple near I∣x∣ = ∞: they become homogeneoils (highest-order derivatives only) with coefficients becoming constant. The simplest example of such an operator is a power of the Laplacian, which was studied in an earlier work. Results on the index of elliptic systems may also be obtained by these methods from the behavior of the Laplacian and the index of singular integral operators in .