Upper semi-continuity of the Royden-Kobayashi pseudo-norm, a counterexample for Hölderian almost complex structures

Sergey Ivashkovich, Sergey Pinchuk, Jean-Pierre Rosay

If $X$ is an almost complex manifold, with an almost complex structure $J$ of class $\CC^α$, for some $\alpha >0$, for every point $p\in X$ and every tangent vector $V$ at $p$, there exi…