Curriculum Vitae

Education:

PhD in Mathematics of Random Systems

Expected completion:  October/2024


MSc in Mathematics


BSc in Mathematics

Experience:

 Advisors:  Jeroen S W Lamb and Martin Rasmussen.

 Financial support: Imperial College President's PhD Scholarship and by the  EPSRC Centre for Doctoral Training in Mathematics of Random Systems: Analysis, Modelling and Simulation (EP/S023925/1).

 

Advisors: Ricardo Miranda Martins and Jeroen S W Lamb.

Financial support: Scholarship from FAPESP (São Paulo Research Foundation). Project here.


Advisors: Ricardo Miranda Martins.

Financial support: Scholarship from FAPESP (São Paulo Research Foundation). Project here.


Advisors: Ricardo Miranda Martins.

Financial support: Scholarship from FAPESP (São Paulo Research Foundation). Project here.

Participation in events:

Poster Presentation Quenched exponential decay of correlations for predominantly expanding multimodal circle maps.  Workshop page.


Poster Presentation Quenched exponential decay of correlations for predominantly expanding multimodal circle maps.  Conference page.


Delivered a presentation with the title On the quasi-ergodicity of absorbing Markov chains with unbounded transition densities, including random logistic maps with escape.  Conference page.


Poster Presentation Quenched exponential decay of correlations for predominantly expanding multimodal circle maps.  Conference page.


Poster Presentation On the quasi-ergodicity of absorbing Markov chains, including random logistic maps with escapeConference page.


Delivered a presentation with the title Quasi-ergodic measures for absorbing Markov processes. Workshop page.


Delivered a presentation with the title Existence and uniqueness of quasi-stationary and quasi-ergodic measures for absorbing Markov chains: a Banach lattice approach. Workshop page.


Local workshop among  Freie Universität Berlin, Max Planck Institute and Imperial College London, organised by Maximilian Engel (FUB) and Zachary Adams (MPG). Delivered a presentation on the logistic Markov process with escape.


Delivered a presentation with the title Existence and Uniqueness of Quasi-stationary and Quasi-ergodic Measures for Absorbed Markov Processes”.  Event Page.


Delivered a presentation with the title Existence and Uniqueness of Quasi-stationary and Quasi-ergodic Measures for Absorbed Markov Processes}. Workshop Page.


Delivered a presentation with the title Existence and Uniqueness of Quasi-stationary and Quasi-ergodic Measures for Absorbed Markov Processes. Event Page.


Poster presentation Piecewise Linear Dynamic Systems: Local and Global Theory. Proceedings here. (only in Portuguese).

Other activities:


Title: Stochastic Stability of Equilibrium Measures via Quasi-ergodic Measures.

Title: A Description of Natural Measures via Quasi-ergodicity.


Title: On the quasi-ergodicity of absorbing Markov processes.


Title: Conditioned random dynamics and quasi-ergodic measures.


Title: Quasi-ergodic measures for random dynamical systems


Title: Quasi-ergodic measures for absorbing Markov chains with applications to random logistic maps with escape



Title: Conditioned dynamics for random dynamical systems.


Title: Quasi-stationary and quasi-ergodic measures for random dynamical systems with escape.

Publications and Preprints:

-with Bernat Bassols-Cornudella, Jeroen Lamb.
Abstract: We propose a notion of conditioned stochastic stability of invariant measures on repellers: we consider whether quasi-ergodic measures of absorbing Markov processes, generated by random perturbations of the deterministic dynamics and conditioned upon survival in a neighbourhood of a repeller, converge to an invariant measure in the zero-noise limit. Under suitable choices of the random perturbation, we find that equilibrium states on uniformly expanding repellers are conditioned stochastically stable. In the process, we establish a rigorous foundation for the existence of “natural measures”, which were proposed by Kantz and Grassberger in 1984 to aid the understanding of chaotic transients.  DOI: arXiv:2405.01343v1.

-with Giuseppe Tenaglia.  

Abstract: In this paper, we study the random dynamical system $f_\omega^n$  generated by a family of maps $\{f_{\omega_0}: \mathbb S^1 \to \mathbb S^1\}_{\omega_0 \in [-\varepsilon,\varepsilon]},$ $f_{\omega_0}(x) = \alpha \xi (x+\omega_0) +a\ (\mathrm{mod }\ 1),$ where $\xi: \mathbb S^1 \to \mathbb R$ is a non-degenerated map, $a\in [0,1)$, and $\alpha,\varepsilon>0$. Fixing a constant $c\in (0,1)$, we show that for $\alpha$ sufficiently large and $\varepsilon > \alpha^{-1+c},$ the random dynamical system $f_\omega^n$ presents a random Young tower structure and quenched decay of correlations. DOI: arXiv:2303.16345


-with Vincent P. H. Goverse, Jeroen S. W. Lamb, Martin Rasmussen. 

Abstract: In this paper, we consider absorbing Markov chains $X_n$ admitting a quasi-stationary measure $\mu$ on $M$ where the transition kernel $\mathcal P$ admits an eigenfunction $0\leq \eta\in L^1(M,\mu)$. We find conditions on the transition densities of $\mathcal P$ with respect to $\mu$, which ensure that $\eta(x) \mu(d x)$ is a quasi-ergodic measure for $X_n$ and that the Yaglom limit converges to the quasi-stationary measure $\mu$-almost surely.  We apply this result to the random logistic map $X_{n+1} = \omega_n X_n (1-X_n)$  absorbed at $\mathbb R \setminus [0,1],$ where $\omega_n$ is an i.i.d sequence of random variables uniformly distributed in $[a,b],$ for $1\leq a <4$ and $b>4.$ DOI: https://doi.org/10.1017/etds.2023.69.


-with Dennis Chemnitz, Hugo Chu, Maximilian Engel, Jeroen S. W. Lamb, Martin Rasmussen.

Abstract: We establish the existence of a full spectrum of Lyapunov exponents for memoryless random dynamical systems with absorption. To this end, we crucially embed the process conditioned to never being absorbed, the Q-process, into the framework of random dynamical systems, allowing us to study multiplicative ergodic properties. We show that the finite-time Lyapunov exponents converge in conditioned probability and apply our results to iterated function systems and stochastic differential equations. DOI: https://doi.org/10.48550/arXiv.2204.04129. To appear in Annales Henri Poincaré.


-with Jeroen S. W. Lamb, Guilermo Olicón-Méndez, Martin Rasmussen.

Abstract: We establish existence and uniqueness of quasi-stationary and quasi-ergodic measures for almost surely absorbed discrete-time Markov chains under weak conditions. We obtain our results by exploiting Banach lattice properties of transition functions under natural regularity assumptions. DOI: https://doi.org/10.1016/j.spa.2024.104364. 


-with Ricardo M. Martins, Douglas D. Novaes.

Abstract:  Vishik's Normal Form provides a local smooth conjugation with a linear vector field for smooth vector fields near contacts with a manifold. In the present study, we focus on the analytic case. Our main result ensures that for the analytic vector field and manifold, the conjugation with Vishik's normal form is also analytic. As an application, we investigate the analyticity of Poincaré Half Maps defined locally near contacts between the analytic vector field and manifold. DOI: https://doi.org/10.1016/j.jde.2021.02.011.

Programming Languages:

PDF version (Outdated):

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