Hello my friends
I have a problem with initial condition for below system of differential equation
sys := {6*(diff(a(t), t))^2+12*a(t)*(diff(a(t), t$2))-3*a(t)^2*phi(t)^(-2*c)*sqrt(1-alpha*(diff(phi(t), t))^2), 2*c*a(t)^3*phi(t)^(-2*c-1)*sqrt(1-alpha*(diff(phi(t), t))^2)-3*alpha*a(t)^2*phi(t)^(-2*c)*(diff(a(t), t))*(diff(phi(t), t))/sqrt(1-alpha*(diff(phi(t), t))^2)-alpha*a(t)^3*phi(t)^(-2*c)*(diff(phi(t), t$2))/sqrt(1-alpha*(diff(phi(t), t))^2)+2*c*alpha*a(t)^3*phi(t)^(-2*c-1)*(diff(phi(t), t))^2/sqrt(1-alpha*(diff(phi(t), t))^2)-alpha^2*a(t)^3*phi(t)^(-2*c)*(diff(phi(t), t))^2*(diff(phi(t), t$2))/(1-alpha*(diff(phi(t), t))^2)^(3/2), R(t) = 6*((diff(a(t), t))^2/a(t)^2+(diff(a(t), t$2))/a(t)), W(t) = -phi(t)^(-2*c)*sqrt(1-alpha*(diff(phi(t), t))^2)/(1/a(t)^3+a(t)^3+phi(t)^(-2*c)/sqrt(1-alpha*(diff(phi(t), t))^2))}
I set {c,alpha}={1,1} but initial conditon is problem ... since I got the following message from maple to illustrate diagrams of W(t), a(t) and even phi(t)
Warning, cannot evaluate the solution past the initial point, problem may be complex, initially singular or improperly set up
please help me.
with the best regard