A sharp lower bound for the scalar curvature of certain steady gradient   Ricci solitons
  We show that the scalar curvature of a steady gradient Ricci soliton satisfying that the ratio between the square norm of the Ricci tensor and the square of the scalar curvature is bounded by one half, is boundend from below by the hyperbolic secant of one half the distance function from a fixed point. 
Manuel Fernandez-Lopez, Eduardo Garcia-Rio
math.DG