Extremal effective divisors of Brill-Noether and Gieseker-Petri type in   $\overline{\mathcal M}_{1,n}$
  We show that certain divisors of Brill-Noether and Gieseker-Petri type span extremal rays of the effective cone in the moduli space of stable genus one curves with $n$ ordered marked points. In particular, they are different from the infinitely many extremal rays found in \cite{ChenCoskun}. 
Dawei Chen, Anand Patel
math.AG