Adrian Navas | Searcharxiv

arXiv2026

Recent Analytical and Computational Developments on the Advection-Diffusion-Reaction Wildfire Model

Wildfires represent a problem for ecosystems, human activities, and economies, driven by the climate crisis and land-use changes. Predicting wildfire propagation through mathematical modelling is essential for damage mitigation and risk assessment. This paper provides a comprehensive review of a physics-based Advection-Diffusion-Reaction (ADR) model, focusing on the balance between physical accuracy and computational efficiency. We analyze the ability of the ADR model to estimate fire front speed and behaviour and discuss its preliminary mathematical properties. Additionally, we discuss some modelling improvements which enhance the physical realism of the model. Furthermore, we address the challenge of reducing computational costs, emphasizing the need for inexpensive but precise numerical schemes. We report recent findings outlining open challenges in model discretization and technological solutions. All these developments highlight the potential of ADR models as powerful tools for efficient wildfire simulation and risk assessment.

math.AP↗

arXiv2014

Hysteretic transitions in the Kuramoto model with inertia

We report finite size numerical investigations and mean field analysis of a Kuramoto model with inertia for fully coupled and diluted systems. In particular, we examine for a Gaussian distribution of the frequencies the transition from incoherence to coherence for increasingly large system size and inertia. For sufficiently large inertia the transition is hysteretic and within the hysteretic region clusters of locked oscillators of various sizes and different levels of synchronization coexist. A modification of the mean field theory developed by Tanaka, Lichtenberg, and Oishi [Physica D, 100 (1997) 279] allows to derive the synchronization profile associated to each of these clusters. We have also investigated numerically the limits of existence of the coherent and of the incoherent solutions. The minimal coupling required to observe the coherent state is largely independent of the system size and it saturates to a constant value already for moderately large inertia values. The incoherent state is observable up to a critical coupling whose value saturates for large inertia and for finite system sizes, while in the thermodinamic limit this critical value diverges proportionally to the mass. By increasing the inertia the transition becomes more complex, and the synchronization occurs via the emergence of clusters of whirling oscillators. The presence of these groups of coherently drifting oscillators induces oscillations in the order parameter. We have shown that the transition remains hysteretic even for randomly diluted networks up to a level of connectivity corresponding to few links per oscillator. Finally, an application to the Italian high-voltage power grid is reported, which reveals the emergence of quasi-periodic oscillations in the order parameter due to the simultaneous presence of many competing whirling clusters.

cond-mat.dis-nn↗