Testing Extended General Relativity with galactic sizes and compact   gravitational sources
  Considering a five-dimensional (5D) Riemannian spacetime with a particular stationary Ricci-flat metric, we have applied the recently developed Extended General Relativistic theory to calculate the lower limit for the size of some relevant galaxies: the Milky Way, Andromeda and M87. Our results are in very good agreement with observations. 
Mariano Anabitarte, Mat\'ias Reynoso, Pablo Alejandro S\'anchez,   Jes\'us Mart\'in Romero and Mauricio Bellini
gr-qc astro-ph.GA physics.space-ph