A new bound on the Morse index of constant mean curvature tori of   revolution in $\mathbb{S}^3$
  In this work we give a new lower bound on the Morse index for constant mean curvature tori of revolution immersed in the three-sphere $\mathbb{S}^3$, by computing some explicit negative eigenvalues for the corresponding Jacobi operator. 
Antonio Ca\~nete
math.DG