Seminar | September 19 | 3:40-5 p.m. | 891 Evans Hall
Cristian Gavrus, UC Berkeley
The aim of this talk is to present the construction of a parametrix for the wave equation with variable coefficients due to Hart Smith. The idea is to write approximate solutions as linear combinations of wave packets by decomposing the initial data using a frame of functions (concentrated in space and frequency) which are then transported across the bicharacteristic flow. Even though this construction and proof are fairly elementary, it works under minimal assumptions on the regularity of the coefficients (two bounded derivatives). The talk is based on the paper https://eudml.org/doc/75304 .