(Color online) The ESPPs with ϕ ( 1 ) > 0 for μ > μ c , u 0 = 0.01 , σ = 0.25, μ = 0.7, κ 1 = 20 , κ 2 = 3 , α = 0.5, δ = 15 (dashed curve), δ = 30 (solid curve), and δ = 45 (dotted curve).