In this second volume (4 volume work), Lars H rmander looks at operators with constant coefficients. An analysis of the existence and regularity of (fundamental) solutions in the first two chapters is followed by a thorough study of the Cauchy problem. He then moves on to cover spectral theory of short range perturbations of operators with constant coefficients, and Fourier-Laplace representations of solutions of homogeneous differential equations with constant coefficients. The last chapter presents a study of the closely related subject of convolution operators.