Local well-posedness for low regularity data for the higher dimensional Maxwell-Klein-Gordon system in Lorenz gauge

The Cauchy problem for the Maxwell-Klein-Gordon equations in the Lorenz gauge in n space dimensions (n ≥ 4) is shown to be locally well-posed for low regularity (large) data. The result relies on the null structure for the main bilinear terms, which was shown to be present not only in the Coulomb gauge but also in the Lorenz gauge by Selberg and Tesfahun, who proved global well-posedness for finite energy data in three space dimensions. This null structure is combined with product estimates for wave-Sobolev spaces. Crucial for the improvement are the solution spaces introduced by Klainerman-Selberg.