Category: Epidemiology

Summary: Estimating when coupling to a dormant pathogen reservoir turns a single antigenic escape cloud into two balanced escape lobes across an immune-imprinting valley.

Pathogens evolve on antigenic landscapes shaped by cross-immunity and by immune imprinting from past exposure. This experiment asks whether a dormant or latent reservoir can qualitatively change that landscape, converting one broad escape region into two comparable escape peaks once the central immune valley becomes deep enough.

The code builds dense symmetric operators that couple active antigenic states to dormant reservoir states, then uses iterative deepening and repeated eigensolves to bisect the critical valley depth across system sizes from N=64 to 2048. It tracks how much of the leading mode sits in the left and right escape lobes, how much remains on the bridge through the valley, and how extended the mode is overall.

That makes the project a structural transition study of immune escape rather than a simple growth-rate calculation. The goal is to identify the point where a reservoir stops merely preserving persistence and starts supporting a genuinely bifurcated pattern of escape across antigenic space.

Method: Dense symmetric eigensolves with iterative deepening and bisection on immune-valley depth at fixed seedbank coupling across N=64 to 2048.

What is measured: Critical valley-depth estimate, bifurcation ratio, peak balance, escape-split fraction, left and right escape mass, bridge mass, dormant bridge mass, participation ratio, and leading eigenvalue.