Solving the Non-Linear ODE: Seeking Help

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    Non-linear Ode
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Discussion Overview

The discussion revolves around solving a non-linear ordinary differential equation (ODE) that arises from field equations of a physical system. Participants explore potential methods for finding an analytic solution, considering the complexity of the equation and the nature of the functions involved.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant presents a non-linear ODE involving a function x(r) and known algebraic functions p0, p1, and p2, seeking methods for an analytic solution.
  • Another participant suggests that there might not be an analytical solution for the presented ODE.
  • A different participant inquires about the presence of small parameters in the problem, proposing that if p1/p0 and p2/p0 are much less than 1, regular perturbation theory might be applicable for finding a solution.
  • A later post introduces a different equation involving temperature, expressing frustration and seeking assistance, but it is unclear how this relates to the original ODE discussion.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the existence of an analytical solution for the original ODE, with some suggesting it may not be possible while others propose methods contingent on certain assumptions.

Contextual Notes

The discussion includes assumptions about the parameters involved, such as the ratios of p1 and p2 to p0, which may affect the applicability of proposed methods. The introduction of a different equation raises questions about its relevance to the original topic.

gizsim
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Hi.
In the course of trying to solve the field equations of a physical system, within some assumptions about its symetry, i managed to get a non-linear ODE involving only a single function of one variable, but still rather tough to handle :
In the equation, x=x(r) is the unknown function to find, and p0, p1, p2 are KNOWN algebraic functions of r (that i didn't take the time to write down here, but are not too complicated functions).

p0*(x''-x'²) + x'(x²+2x) (-/+) p1*x^4 + p2*x³ - p2*x² (+/-) p1*x = 0

Do you guys have any ideas of how i could manage to obtain any analytic solution for x(r)?
I can't find any help, because its not a categorized equation (Ricatti, Abell, ...)
Thank you so much for your help!
 
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There might not be an analytical solution for that PDE.
 
Are there any small parameters in the problem?

If for example p1/p0 << 1 and p2/p0 << 1 then you might be able to find a solution using regular perturbation theory.
 
How to solve a equation of this kind

T' = a*(T^4 - r^4) + b*(T^4 - s^4) + P*(1 - eta(T))

The above equation is driving me nuts... the 'eta' is a function of T(Temperature) and initial value of T is known.
Say at t = 0 T is 298
Need help! Please!
 

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