conditions

topology types

2 e 2 δ r < μ i < 2 e + 2 δ r ,

max { 0 , δ r μ i 2 e + d 2 1 } < ω i 1 4 ( δ r μ i 2 e ) 2 + d 2

stable node

or μ i < 4 ( 1 d 2 ) + 2 e 2 δ r ,

max { d 2 , 1 4 ( δ r μ i 2 e ) 2 + d 2 } < ω i 1 + d 2

μ i < 2 e 2 δ r , 1 + d 2 < ω i 1 4 ( δ r μ i 2 e ) 2 + d 2

unstable node

or μ i > 2 e + 2 δ r , 1 + d 2 < ω i 1 4 ( δ r μ i 2 e ) 2 + d 2

μ i > 2 e + 1 d 2 δ r , 0 < ω i < δ r μ i 2 e + d 2 1

saddle

ω i > max { 1 + d 2 , 1 4 ( δ r μ i 2 e 2 ) + d 2 }

unstable focus

ω i = δ r μ i 2 e + d 2 1

non-hyperbolic

2 e 2 δ r < μ i < 2 e + 2 δ r ω i = d 2 + 1