Continuous rational functions on real and $p$-adic varieties
  This note studies, and partially solves, 3 elementary questions about continuous rational functions on real (and p-adic) algebraic varieties: Can one restrict such a function to a subvariety? Can one extend such a function from a subvariety? Which linear equations can be solved using such functions? 
J\'anos Koll\'ar (Princeton Univ)
math.AG