@phdthesis{Hohberger2006, author = {Hohberger, Horst}, title = {Semiclassical asymptotics for the scattering amplitude in the presence of focal points at infinity}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-11574}, school = {Universit{\"a}t Potsdam}, year = {2006}, abstract = {We consider scattering in \$\R^n\$, \$n\ge 2\$, described by the Schr\"odinger operator \$P(h)=-h^2\Delta+V\$, where \$V\$ is a short-range potential. With the aid of Maslov theory, we give a geometrical formula for the semiclassical asymptotics as \$h\to 0\$ of the scattering amplitude \$f(\omega_-,\omega_+;\lambda,h)\$ \$\omega_+\neq\omega_-\$) which remains valid in the presence of focal points at infinity (caustics). Crucial for this analysis are precise estimates on the asymptotics of the classical phase trajectories and the relationship between caustics in euclidean phase space and caustics at infinity.}, subject = {Mathematik}, language = {en} }