3 papers
q-bio.PE2026
Network amplification of dengue declines as endemicity rises: climate-adjusted directional spread across Costa Rican cantons, 1993-2012
Fabio Sanchez
\textbf{Background:} In Costa Rica, dengue is reported and controlled at the canton level, and outbreaks in one canton are often followed by outbreaks in others. Climate models des…
math.DS2026
What Deletes: Eigenvectors, Non-Normality, and the Social Content of the Basic Reproduction Number
Fabio Sanchez
The basic reproduction number is the spectral radius of a matrix, . Taking that definition literally, we ask what discards. A matrix carries three kinds…
math.DS2026
When Self-Protection Backfires: Adaptive Contact Behavior Expands the Endemic Basin in an Addiction Model with Nonlinear Relapse
Fabio Sanchez
We extend the Susceptible--Addicted--Reformed (SAR) model of \cite{sanchez2023}, which exhibits a forward--backward bifurcation driven by nonlinear relapse, by embedding an epi-eco…