Rogue waves driven by underwater forcing in channels  

Project: FONDECYT postdoctorado 3200499 (April 2020 - April 2023)

Rogue waves are large amplitude waves suddenly appearing on the ocean's surface, in basins of arbitrary depth with and without strong currents. Many linear, nonlinear and probabilistic theories have emerged since the first confirmation of their existence. However, the physical mechanisms that give rise to such events are still controversial. Understanding the phenomenon of rogue waves would be very useful in forecasting, implementing protocols and selecting areas with a higher risk of rogue wave occurrence based on the oceanographic and meteorological conditions of the zones. We study rogue wave generation in annular water channels by a random underwater forcing. The main goal of this project is to shed light on the real mechanism of rogue wave formation and to elucidate the true role of randomness, dispersion, resonance, and nonlinearity.

Localised Faraday patterns induced by heterogeneous parametric drive  

Projects:

• CONICYT PFCHA doctorado nacional 21150292 (May 2015 - December 2018)

• USACH DICYT postdoctorado USA1899-Vridei041931YZ-PAP (January 2019 - January 2020)

When a fluid is subjected to vertical vibrations, a pattern can be generated on the surface if the amplitude of the oscillations is above a certain threshold. This is the Faraday instability,  where waves oscillate at half the forcing frequency. Although these patterns have been widely investigated in the past, the case of the heterogeneous drive is less explored [1]. Motivated by systems in which uniform drive is not plausible, this project aims to investigate theoretically, numerically and experimentally the generation of localised Faraday patterns induced by a localised parametric drive. Using a heterogeneous parametrically driven nonlinear Schrödinger equation as a model, we perform a complete nonlinear analysis of the system to understand theoretically nonlinear saturation phenomena, drift instabilities and spatiotemporal chaos.

Dynamics of soliton-bubbles in Josephson junctions

Project: CONICYT PFCHA doctorado nacional 21150292 (May 2015 - January 2018)

The transmission, reflection, and annihilation of waves that go from one medium to another or collide with a localised defect is a widespread problem in physics. Such a problem appears in many situations, from quantum mechanical to electrodynamical phenomena. A crucial point to consider is that more complicated and fascinating phenomena can occur when such waves are nonlinear! When such waves have an internal structure, such as in the case of sine-Gordon solitons, the presence of localised but not point-like heterogeneities can cause the destabilisation of internal modes, producing bubble-like and drop-like structures that are sustained by the same heterogeneities that create them. This project aims to investigate the formation, stability and controlled transport of this kind of localised structures in Josephson junctions.

Dynamics of kinks and true-vacuum bubbles in nonlinear field theories

Projects:

• CONICYT PFCHA doctorado nacional 21150292 (May 2015 - January 2018). 

• USACH DICYT postdoctorado 042031GZ_POSTDOC (March 2020 - April 2020)

First-order phase transitions in nonlinear field theories are important problems in particle physics and cosmology. The underlying phenomenon is that of bubble nucleation, which can be triggered by a nonlinear instability that is energetically above a nucleation barrier. Such nucleation usually occurs around an impurity, such as tiny black holes, and has important implications in vacuum stability, quark confinement, and cosmological models. This project aims to study the dynamics of soliton bubbles in nonlinear Klein-Gordon systems using Higgs-like potentials that are relevant in vacuum decay problems. I'm interested in phenomena such as vacuum decay seeded by small heterogeneities and anomalous effects due to infinite-action instantons.