Static Solutions with Spherical Symmetry in f(T) Theories
  The spherically symmetric static solutions are searched for in some f(T)
models of gravity theory with a Maxwell term. To do this, we demonstrate that
reconstructing the Lagrangian of f(T) theories is sensitive to the choice of
frame, and then we introduce a particular frame based on the conformally
Cartesian coordinates. In this particular frame, the existence conditions of
various solutions are presented. Our results imply that only a limited class of
f(T) models can be solved in this frame. For more general models, the search
for spherically symmetric static solutions is still an open and challenging
problem, hopefully solvable in other frames.
