activity
20242026
collaborators

6 papers

math.DS2026

Singular Suspension Flows and Infinite Topological Entropy

Jonatas Marinho S. Araujo, Sergio Romaña

We construct a dense set of homeomorphisms with infinite topological entropy whose associated pseudo-singular suspension flows have finite entropy -- and indeed, arbitrarily small…

math.DS2026

Robust transitivity of geodesic flows from metrics with conjugate points

Ygor de Jesus, Luis Pedro Piñeyrúa, Sergio Romaña

In this article, we prove a general criterion for obtaining robust transitivity of partially hyperbolic geodesic flows. As a consequence, we exhibit the first example of a op…

math.DS2026

On the Birkhoff Spectrum for Hyperbolic Dynamics

Sergio Romaña

In this paper, we study the structure of Birkhoff spectra for hyperbolic dynamical systems. Given a Hölder observable \(f\) on a basic set \(Λ\), we obtain the following results:…

math.DS2025

Curvature Rigidity Through Level Sets of Lyapunov Exponents in Geodesic Flows

Sergio Romaña

In this paper, we establish new geometric rigidity results through the study of Lyapunov exponent level sets via invariant measures. First, we prove that for a manifold without…

math.DS2025

Entropy of Singular Suspensions

Elias Rego, Sergio Romaña

In this work, we investigate diffeomorphisms whose positiveness of topological entropy is destroyed by singular suspensions. We show that this phenomenon is rare in the set of $C^1…

math.DS2024

Partially hyperbolic geodesic flow via conformal deformation

Ygor de Jesus, Luis Pedro Piñeyrúa, Sergio Romaña

This paper presents a new construction of non-Anosov Partially Hyperbolic Geodesic flows. Our construction is closely related to the construction made by Carneiro and Pujals, the n…