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Theory and Modern Applications

Table 12 Critical bifurcation values for endemic equilibrium of the ELM models

From: Andronov–Hopf and Neimark–Sacker bifurcations in time-delay differential equations and difference equations with applications to models for diseases and animal populations

Version

1(dnn)

3(nnd), 7(ddd)

5(dnd)

6(ndd)

Range of \(R_{0}\)

\(1< R_{0}<2\)

\(R_{0}>1\)

\(R_{0}>1\)

\(R_{0}>2\)

γ = 2

\(1< R_{0}<1+\frac{2}{\gamma }\)

  

\(R_{0}>1+\frac{2}{\gamma}\)

\(R_{0}\)

1.02

1.98

1.98

1.98

2.48

ρ

2.88

−2.88

0

3

−3

η

3

3

5.88

8.88

5.88

DDE

\(\tau _{c}\)

0.3379

3.402

0.2671

0.1467

0.4165

\(\phi _{c}\)

0.8400

0.8400

5.880

8.358

5.057

\(\frac{d\mu }{d\tau } \vert _{\tau _{c}}\)

8.682

5.655e−3

9.971

38.45

2.693

Discrete

\(\tau _{c}\)

m = 22

0.3376

2.6737

0.2612

0.14486

0.3958

m = 23

0.3377

2.7012

0.2614

0.14494

0.3967

\(\omega _{c}\)

m = 22

0.0126

0.1267

0.0698

0.0545

0.0936

m = 23

0.0121

0.1213

0.0668

0.0522

0.0896

\(\frac{dr}{d\tau } \vert _{\tau _{c}}\)

m = 22

0.0058

1.499e−4

0.0060

0.0119

0.0030

m = 23

0.0053

1.358e−4

0.0055

0.0109

0.0028

\(\Re [e^{-i\omega _{c}}c_{1} (\tau _{c} ) ]\)

m = 22

0.6968

0.0889

(3) −0.0086

−0.0063

−0.0240

   

(7) −0.0280

  

m = 23

0.6692

0.0855

(3) −0.0082

−0.0060

−0.0230

   

(7) −0.0268