On Polyquadratic Twists of X_0(N)
  In this paper, we study the local points of the twist of X_0(N) by a polyquadratic field and give an algorithm to produce such curves which has local points everywhere. Then we investigate violations of the Hasse Principle for these curves and give an asymptotic for the number of such violations. Finally, we study reasons of such violations. 
Ekin Ozman
math.NT math.AG