Circular Motion - System of Differential Equations

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The following system of differential equations describes a charged particle in a viscous medium enveloped in an EM field,
$$partial^2_t x(t) = acos(omega t +phi)y +bx +cpartial_t y -dpartial_t x$$
$$partial^2_t y(t) = acos(omega t +phi)x +by -cpartial_t x -dpartial_t y$$



All of the coefficients are real and positive. It's well known there are two circular eigenmotions. Given this, it seems useful to make the change of variables $u(t)=x(t)+i y(t)$. Doing so produces,
$$partial^2_t u(t) = aicos(omega t +phi)u^* +bu -(d+ic)partial_t u$$



In the case of $a=d=0$, a solution of $u(t)=exp(-iw_0t)$ exists with $w_0$ holding two values based on $b$ and $c$. It can be assumed $partial_t x(0)=partial_t y(0)=0$



Any suggestions on how to proceed further? If it makes the problem significantly easier, the case of $d=0$ is also of great interest.







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  • What if you subtract the two equations and solve for the variable $z(t)=x(t)-y(t)$ could it be of any help? Edit: just noticed that the first partial derivative with respect to time don't have the same sign so probably it wouldn't help...maybe choosing a new variable $e=-c$ just for the second equation?
    – Davide Morgante
    Aug 3 at 22:35











  • How do you define $rho_1$, $rho_2$, etc?
    – Robert Lewis
    Aug 3 at 22:41






  • 1




    @Robert, I've updated the question to clarify
    – Captain Morgan
    Aug 3 at 22:44










  • What's the question? I can only see statements.
    – md2perpe
    Aug 7 at 16:54










  • @md2perpe, thanks
    – Captain Morgan
    Aug 7 at 16:57














up vote
2
down vote

favorite












The following system of differential equations describes a charged particle in a viscous medium enveloped in an EM field,
$$partial^2_t x(t) = acos(omega t +phi)y +bx +cpartial_t y -dpartial_t x$$
$$partial^2_t y(t) = acos(omega t +phi)x +by -cpartial_t x -dpartial_t y$$



All of the coefficients are real and positive. It's well known there are two circular eigenmotions. Given this, it seems useful to make the change of variables $u(t)=x(t)+i y(t)$. Doing so produces,
$$partial^2_t u(t) = aicos(omega t +phi)u^* +bu -(d+ic)partial_t u$$



In the case of $a=d=0$, a solution of $u(t)=exp(-iw_0t)$ exists with $w_0$ holding two values based on $b$ and $c$. It can be assumed $partial_t x(0)=partial_t y(0)=0$



Any suggestions on how to proceed further? If it makes the problem significantly easier, the case of $d=0$ is also of great interest.







share|cite|improve this question





















  • What if you subtract the two equations and solve for the variable $z(t)=x(t)-y(t)$ could it be of any help? Edit: just noticed that the first partial derivative with respect to time don't have the same sign so probably it wouldn't help...maybe choosing a new variable $e=-c$ just for the second equation?
    – Davide Morgante
    Aug 3 at 22:35











  • How do you define $rho_1$, $rho_2$, etc?
    – Robert Lewis
    Aug 3 at 22:41






  • 1




    @Robert, I've updated the question to clarify
    – Captain Morgan
    Aug 3 at 22:44










  • What's the question? I can only see statements.
    – md2perpe
    Aug 7 at 16:54










  • @md2perpe, thanks
    – Captain Morgan
    Aug 7 at 16:57












up vote
2
down vote

favorite









up vote
2
down vote

favorite











The following system of differential equations describes a charged particle in a viscous medium enveloped in an EM field,
$$partial^2_t x(t) = acos(omega t +phi)y +bx +cpartial_t y -dpartial_t x$$
$$partial^2_t y(t) = acos(omega t +phi)x +by -cpartial_t x -dpartial_t y$$



All of the coefficients are real and positive. It's well known there are two circular eigenmotions. Given this, it seems useful to make the change of variables $u(t)=x(t)+i y(t)$. Doing so produces,
$$partial^2_t u(t) = aicos(omega t +phi)u^* +bu -(d+ic)partial_t u$$



In the case of $a=d=0$, a solution of $u(t)=exp(-iw_0t)$ exists with $w_0$ holding two values based on $b$ and $c$. It can be assumed $partial_t x(0)=partial_t y(0)=0$



Any suggestions on how to proceed further? If it makes the problem significantly easier, the case of $d=0$ is also of great interest.







share|cite|improve this question













The following system of differential equations describes a charged particle in a viscous medium enveloped in an EM field,
$$partial^2_t x(t) = acos(omega t +phi)y +bx +cpartial_t y -dpartial_t x$$
$$partial^2_t y(t) = acos(omega t +phi)x +by -cpartial_t x -dpartial_t y$$



All of the coefficients are real and positive. It's well known there are two circular eigenmotions. Given this, it seems useful to make the change of variables $u(t)=x(t)+i y(t)$. Doing so produces,
$$partial^2_t u(t) = aicos(omega t +phi)u^* +bu -(d+ic)partial_t u$$



In the case of $a=d=0$, a solution of $u(t)=exp(-iw_0t)$ exists with $w_0$ holding two values based on $b$ and $c$. It can be assumed $partial_t x(0)=partial_t y(0)=0$



Any suggestions on how to proceed further? If it makes the problem significantly easier, the case of $d=0$ is also of great interest.









share|cite|improve this question












share|cite|improve this question




share|cite|improve this question








edited Aug 7 at 16:57
























asked Aug 3 at 22:22









Captain Morgan

33917




33917











  • What if you subtract the two equations and solve for the variable $z(t)=x(t)-y(t)$ could it be of any help? Edit: just noticed that the first partial derivative with respect to time don't have the same sign so probably it wouldn't help...maybe choosing a new variable $e=-c$ just for the second equation?
    – Davide Morgante
    Aug 3 at 22:35











  • How do you define $rho_1$, $rho_2$, etc?
    – Robert Lewis
    Aug 3 at 22:41






  • 1




    @Robert, I've updated the question to clarify
    – Captain Morgan
    Aug 3 at 22:44










  • What's the question? I can only see statements.
    – md2perpe
    Aug 7 at 16:54










  • @md2perpe, thanks
    – Captain Morgan
    Aug 7 at 16:57
















  • What if you subtract the two equations and solve for the variable $z(t)=x(t)-y(t)$ could it be of any help? Edit: just noticed that the first partial derivative with respect to time don't have the same sign so probably it wouldn't help...maybe choosing a new variable $e=-c$ just for the second equation?
    – Davide Morgante
    Aug 3 at 22:35











  • How do you define $rho_1$, $rho_2$, etc?
    – Robert Lewis
    Aug 3 at 22:41






  • 1




    @Robert, I've updated the question to clarify
    – Captain Morgan
    Aug 3 at 22:44










  • What's the question? I can only see statements.
    – md2perpe
    Aug 7 at 16:54










  • @md2perpe, thanks
    – Captain Morgan
    Aug 7 at 16:57















What if you subtract the two equations and solve for the variable $z(t)=x(t)-y(t)$ could it be of any help? Edit: just noticed that the first partial derivative with respect to time don't have the same sign so probably it wouldn't help...maybe choosing a new variable $e=-c$ just for the second equation?
– Davide Morgante
Aug 3 at 22:35





What if you subtract the two equations and solve for the variable $z(t)=x(t)-y(t)$ could it be of any help? Edit: just noticed that the first partial derivative with respect to time don't have the same sign so probably it wouldn't help...maybe choosing a new variable $e=-c$ just for the second equation?
– Davide Morgante
Aug 3 at 22:35













How do you define $rho_1$, $rho_2$, etc?
– Robert Lewis
Aug 3 at 22:41




How do you define $rho_1$, $rho_2$, etc?
– Robert Lewis
Aug 3 at 22:41




1




1




@Robert, I've updated the question to clarify
– Captain Morgan
Aug 3 at 22:44




@Robert, I've updated the question to clarify
– Captain Morgan
Aug 3 at 22:44












What's the question? I can only see statements.
– md2perpe
Aug 7 at 16:54




What's the question? I can only see statements.
– md2perpe
Aug 7 at 16:54












@md2perpe, thanks
– Captain Morgan
Aug 7 at 16:57




@md2perpe, thanks
– Captain Morgan
Aug 7 at 16:57















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