BTZ extensions of globally hyperbolic singular flat spacetimes

Understand

Minkowski space is the local model of 3 dimensionnal flat spacetimes.

• Recent progress in the description of globally hyperbolic flat spacetimes showed strong link between Lorentzian geometry and Teichm{\"u}ller space.
• We notice that Lorentzian generalisations of conical singularities are useful for the endeavours of descripting flat spacetimes, creating stronger links with hyperbolic geometry and compactifying spacetimes.
• In particular massive particles and extreme BTZ singular lines arise naturally.