Penrose's singularity theorem in a Finsler spacetime
  We translate Penrose's singularity theorem to a Finsler spacetime. To that end, causal concepts in Lorentzian geometry are extended, including definitions and properties of focal points and trapped surfaces, with careful attention paid to the differences that arise in the Finslerian setting. 
Amir Babak Aazami, Miguel Angel Javaloyes
math.DG gr-qc math-ph math.MP