We study hyperbolic problems for operators having constant multiplicities in the environment of SG-classes. A well-posedness theorem is obtained and the solution is given in terms of FIOs defined in SG classes, improving previuos results obtained by one of the authors.
Cauchy problem for SG-hyperbolic equations with constant multiplicities / CORIASCO S; RODINO L.. - In: RICERCHE DI MATEMATICA. - ISSN 0035-5038. - 48(1999), pp. 25-43.