Category: Ecology

Summary: Finding when a hostile bridge corridor causes two refuge-pinned population modes to merge and delocalize in a non-Hermitian persistence model.

Spatial persistence can depend on whether favorable habitat patches remain effectively isolated from one another by hostile terrain. This experiment asks when two refuge-supported population lobes, each locally pinned by disorder, stop behaving as separate protected regions and instead merge through a bridge corridor that allows spillover beyond the refuges.

The model uses a dense Hatano-Nelson-style persistence operator with drift, disorder, and two refuge zones connected by a tunable bridge. It repeatedly bisects bridge permeability while increasing system size, then tracks whether the leading mode remains refuge concentrated or escapes into the corridor and surrounding habitat.

That makes the experiment a finite-size map of a coupling threshold rather than a single illustrative simulation. It links ecological refuge questions to non-Hermitian localization physics in a setting where bridge-mediated escape is the central observable.

Method: Dense non-symmetric eigensolve with iterative deepening and bisection on bridge permeability in a dual-refuge persistence operator.

What is measured: Critical bridge-permeability threshold, refuge mass, bridge mass, escape fraction, persistence level, and bracket width.