Searcharxiv⌕ Search

arXiv subjects

Sergio Romaña

Publications and source records attributed to Sergio Romaña.

22 records · Page 2Linked to original sources

Hölder continuous maps on the interval with positive metric mean dimension

Fix a compact metric space $X$ with finite topological dimension. Let $C^{0}(X)$ be the space of continuous maps on $X$ and $ H^α(X)$ the space of $α$-Hölder continuous maps on $X$, for $α\in (0,1].$ $H^{1}(X)$ is the space of Lipschitz continuous maps on $X$. We have $$H^{1}(X)\subset H^β(X) \subset H^α(X) \subset C^{0}(X),\quad\text{ where }0<α<β<1.$$ It is well-known that if $ϕ\in H^{1}(X)$, then $ϕ$ has metric mean dimension equal to zero. On the other hand, if $X$ is a finite dimensional compact manifold, then $C^{0}(X)$ contains a residual subset whose elements have positive metric mean dimension. In this work we will prove that, for any $α\in (0,1)$, there exists $ϕ\in H^α([0,1]) $ with positive metric mean dimension.

math.DS↗

Contributions to the study of Anosov Geodesic Flows in Non-Compact Manifolds

In this paper we prove that if the geodesic flow of a {compact or non-compact} complete manifold without conjugate points is of the Anosov type, then the average of the integral of the sectional curvature along the geodesic is negative and away from zero from a uniform time. Moreover, in dimension two, if the manifold has no focal points, then this condition is sufficient to obtain that the geodesic flow is of Anosov type. This sufficient condition will also be used to construct new examples of non-compact surfaces whose geodesic flow is of the Anosov type.

math.DS↗