Ricci flow and curvature on the variety of flags on the two dimensional   projective space over the complexes, quaternions and the octonions
  For homogeneous metrics on the spaces of the title it is shown that the Ricci flow can move a metric of stricly positive sectional curvature to one with some negative sectional curvature and one of positive definite Ricci tensor to one with indefinite signature. 
Man-Wai Cheung and Nolan R. Wallach
math.DG