In his paper [2], Paul Ehrlich write

> In [1], Aubin stated a theorem which implied as a corollary that **_if a manifold
$M$ admits a Riemannian metric with nonnegative Ricci curvature and
all Ricci curvatures positive at some point, then $M$ admits a metric of everywhere
positive Ricci curvature._** It appears the proof in [1] is incomplete
and the uniformity and correctness of Aubin's estimates even in the compact
case are not clear.

Aubin paper is a bit technical so I want to know is P. Ehrlich claim/objection about correctness or incompleteness of Aubin's proof acceptable?


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  [1]: <cite authors="Aubin, T.">_Aubin, T._, [**Métriques riemanniennes et courbure**](http://dx.doi.org/10.4310/jdg/1214429638), J. Differ. Geom. 4, 383-424 (1970). [ZBL0212.54102](https://zbmath.org/?q=an:0212.54102).</cite>

  [2]: <cite authors="Ehrlich, Paul">_Ehrlich, Paul_, [**Metric deformations of curvature. I: Local convex deformations**](http://dx.doi.org/10.1007/BF00145952), Geom. Dedicata 5, 1-23 (1976). [ZBL0345.53024](https://zbmath.org/?q=an:0345.53024).</cite>