Type: Article
Publication Date: 2003-11-13
Citations: 55
DOI: https://doi.org/10.1090/s0894-0347-03-00445-4
We prove that the evolution problem for the MaxwellâKleinâ Gordon system is locally well posed when the initial data belong to the Sobolev space $H^{\frac {1}{2} + \epsilon }$ for any $\epsilon > 0$. This is in spite of a complete failure of the standard model equations in the range $\frac {1}{2} < s < \frac {3}{4}$. The device that enables us to obtain inductive estimates is a new null structure which involves cancellations between the elliptic and hyperbolic terms in the full equations.