Differential equations with singularities

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The discussion centers on solving coupled differential equations with singularities, specifically two equations involving functions f(r) and g(r). The user believes that an analytical solution is not feasible, even when the coupling parameter a is set to zero, and seeks numerical methods for resolution. They attempted to use MATLAB's bvp4c but encountered issues due to the second-kind singularities. The user is looking for assistance in reformulating the equations for use with ode45, noting that dividing by r^2 leads to similar singularity problems. The conversation highlights the challenges of numerical solutions in the presence of singularities in differential equations.
kosmonautilus
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I have to solve the following coupled differential equations

d^2f(r)/dr^2+1/r*df(r)/dr+(2-2*f(r)^2-2*a*g(r)^2-l_1^2/r^2)*f(r)=0

d^2g(r)/dr^2+1/r*dg(r)/dr+(2-2*g(r)^2-2*a*f(r)^2-l_2^2/r^2)*g(r)=0,

where a is the coupling. I think that it is not possible to solve it analytically (even in case a==0), so i have to do it numerically. I tried it with matlab, but bvp4c can not solve equations with singularities of second kind. Can somebody help me? (I'm a advanced user of matlab)
 
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Thank you, but for ode45 I need the 4 equations in the form dydx=... To obtain this, I have to divide by r^2 again and I have the same problem with the singularities
dy(1)=y(2)
r^2*dy(2)= r*y(2)+...
 

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