I have the following set of 14 differential equations with the variables listed. When I run it, a message comes “Repeated convergence test failure..”
\[Alpha] = 1.5; \[CapitalDelta]1 = 2 \[Pi]*1.45*10^6; \[CapitalDelta]2 = 2 \[Pi]*1.45*10^6; k1 = 2 \[Pi]*759*10^3; k2 = 2 \[Pi]*759*10^3; g1[k1_, k2_, \[Alpha]_] = \[Alpha]/4 (k1 + k2); A1[k1_, \[CapitalDelta]1_] = (I*k1)/2 - \[CapitalDelta]1; A2[k2_, \[CapitalDelta]2_] = (I*k2)/2 - \[CapitalDelta]2; (*System of equations*) system := { x1'[t] == I*A1[k1, \[CapitalDelta]1]* x1[t] + I* g1[k1, k2, \[Alpha]] *x2[t] , x2'[t] == -I*x2[t] + I *g1[k1, k2, \[Alpha]]*x1[t] , x3'[t] == -I*A1[k1, \[CapitalDelta]1]*x3[t] - I*g1[k1, k2, \[Alpha]]*x4[t], x4'[t] == I*A2[k2, \[CapitalDelta]2]*x4[t] - I *g1[k1, k2, \[Alpha]]*x3[t], x5'[t] == 2*I*A1[k1, \[CapitalDelta]1]*x5[t] + 2*I*g1[k1, k2, \[Alpha]]*x1[t]*x2[t], x6'[t] == -2*I*A2[k2, \[CapitalDelta]2]*x6[t] - 2*I*g1[k1, k2, \[Alpha]]*x1[t]*x2[t], x7'[t] == -2*I*A1[k1, \[CapitalDelta]1]*x7[t] - 2*I*g1[k1, k2, \[Alpha]]*x3[t]*x4[t], x8'[t] == 2*I*A2[k2, \[CapitalDelta]2]*x8[t]^2 - 2*I*g1[k1, k2, \[Alpha]]*x3[t]*x4[t], x9'[t] == I*g1[k1, k2, \[Alpha]]*(x3[t]*x2[t] - x4[t]*x1[t]), x10'[t] == I*g1[k1, k2, \[Alpha]]*(x4[t]*x1[t] - x3[t]*x2[t]), x11'[t] == I*(A1[k1, \[CapitalDelta]1] - A2[k2, \[CapitalDelta]2]) x11[t] + I*g1[k1, k2, \[Alpha]]*(x2[t]^2 - x1[t]^2), x12'[t] == I*(A1[k1, \[CapitalDelta]1] + A2[k2, \[CapitalDelta]2])*x12[t] + I*g1[k1, k2, \[Alpha]]*(x2[t]*x4[t] - x1[t]*x3[t]), x13'[t] == -I*(A1[k1, \[CapitalDelta]1] + A2[k2, \[CapitalDelta]2])* x13[t] + I*g1[k1, k2, \[Alpha]]*(x3[t]*x1[t] - x4[t]*x2[t]), x14'[t] == -I*(A1[k1, \[CapitalDelta]1] - A2[k2, \[CapitalDelta]2]) - I*g1[k1, k2, \[Alpha]]*(x4[t]^2 - x3[t]^2)} initialvalues := { x1[0] == 1, x2[0] == 1, x3[0] == 1, x4[0] == 1, x5[0] == 1, x6[0] == 1, x7[0] == 1, x8[0] == 1, x9[0] == 1, x10[0] == 1, x11[0] == 1, x12[0] == 1, x13[0] == 1, x14[0] == 1} sol := Flatten@ NDSolve[Join[system, initialvalues], {x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14}, {t, 0, 6}(*, MaxSteps\[Rule]Infinity*)]; A = Evaluate[{ x9[t]} /. sol]; P11 = Plot[A, {t, 0, 6}, PlotRange -> All]
What is the way to get rid of this problem?
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