On Hessian limit directions along non-oscillating gradient trajectories
  Given a non-oscillating gradient trajectory G of a real analytic function f, we show that the limit v of the secants at the limit point O of G along the trajectory G is an eigen-vector of the limit of the direction of the Hessian matrix Hess (f) at O along G. The same holds true at infinity if the function is globally subanalytic. We also deduce some interesting estimates along the trajectory. 
Vincent Grandjean
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