The minimal regular model of a Fermat curve of odd squarefree exponent   and its dualizing sheaf
  We construct the minimal regular model of the Fermat curve of odd squarefree composite exponent $N$ over the $N$-th cyclotomic integers. As an application, we compute upper and lower bounds for the arithmetic self-intersection of the dualizing sheaf of this model. 
Christian Curilla, J. Steffen M\"uller
math.NT