Deformation space of a non-uniform 3-dimensional real hyperbolic lattice   in quaternionic hyperbolic plane
  In this note, we study deformations of a non-uniform real hyperbolic lattice in quaternionic hyperbolic spaces. Specially we show that the representations of the fundamental group of the figure eight knot complement into PU(2,1) cannot be deformed in $PSp(2,1)$ out of PU(2,1) up to conjugacy. 
Inkang Kim
math.GT