The HADES seminar on Tuesday, **March 8** will be at **3:30 pm** in **Room 740**.

**Speaker**: Arthur Touati

**Abstract**: In this talk, I will present recent work on high-frequency solutions

to the Einstein vacuum equations. From a physical point of view, these solutions

model high-frequency gravitational waves and describe how waves travel on a fixed

background metric. There are also interested when studying the Burnett conjecture,

which addresses the lack of compactness of the family of vacuum spacetimes. These

high-frequency spacetimes are singular and require to work under the regime of

well-posedness for the Einstein vacuum equations. I will review the literature on

the subject and then show how one can construct them in generalised wave gauge

by defining high-frequency ansatz.