Shilnikov Chaos: Homoclinic Spiral Attractor

ρ > |λ| saddle-focus condition • spiraling homoclinic orbits • infinite horseshoes

System Parameters

ẋ = αx − ρy + x(1−r²)
ẏ = ρx + αy + y(1−r²)
ż = −βz + x²

Shilnikov: chaos iff
ρ > |λ| (saddle-focus)
Shilnikov cond: ρ/α = 3.0
Shilnikov's theorem (1965): if a 3D system has a saddle-focus equilibrium with a homoclinic orbit, and the spiral frequency ρ exceeds the saddle quantity |λ|, then countably infinite horseshoes exist near the orbit — guaranteeing chaos.