In this second volume (4 volume work), Lars Hörmander 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.