Solution 3 to problem l2o57


Expressions | Parameters | Relevance | Back to problem l2o57

Expressions

The solution is given through the following expressions:

      560     2
     -----*a15 *a8*b2
      27
b45=------------------
              3
           a13


      280     2
     -----*a15 *a8*b2
      27
b44=------------------
              3
           a13


      280     2
     -----*a15 *a8*b2
      27
b43=------------------
              3
           a13


      112
     -----*a15*a8*b2
       9
b42=-----------------
             2
          a13


      280
     -----*a15*a8*b2
       9
b41=-----------------
             2
          a13


      56
     ----*a15*a8*b2
      3
b40=----------------
             2
          a13


      140
     -----*a15*a8*b2
       9
b39=-----------------
             2
          a13


      112
     -----*a15*a8*b2
       9
b38=-----------------
             2
          a13


      28
     ----*a15*a8*b2
      9
b37=----------------
             2
          a13


      140     3
     -----*a15 *b2
      27
b36=---------------
            3
         a13


      140     3
     -----*a15 *b2
       9
b35=---------------
            3
         a13


      70     2
     ----*a15 *b2
      9
b34=--------------
            2
         a13


      280     2
     -----*a15 *b2
       9
b33=---------------
            2
         a13


      70     2
     ----*a15 *b2
      3
b32=--------------
            2
         a13


      280     2
     -----*a15 *b2
       9
b31=---------------
            2
         a13


      280     2
     -----*a15 *b2
       9
b30=---------------
            2
         a13


      140     2
     -----*a15 *b2
       9
b29=---------------
            2
         a13


      14
     ----*a15*b2
      3
b28=-------------
         a13


     14*a15*b2
b27=-----------
        a13


      70
     ----*a15*b2
      3
b26=-------------
         a13


      70
     ----*a15*b2
      3
b25=-------------
         a13


     14*a15*b2
b24=-----------
        a13


      14
     ----*a15*b2
      3
b23=-------------
         a13


b22=b2


      560        2
     -----*a15*a8 *b2
      27
b21=------------------
              3
           a13


      280     2
     -----*a15 *a8*b2
       9
b20=------------------
              3
           a13


      280     2
     -----*a15 *a8*b2
       9
b19=------------------
              3
           a13


      280
     -----*a15*a8*b2
       9
b18=-----------------
             2
          a13


      560
     -----*a15*a8*b2
       9
b17=-----------------
             2
          a13


      560
     -----*a15*a8*b2
       9
b16=-----------------
             2
          a13


      140
     -----*a15*a8*b2
       3
b15=-----------------
             2
          a13


      560
     -----*a15*a8*b2
       9
b14=-----------------
             2
          a13


      140
     -----*a15*a8*b2
       9
b13=-----------------
             2
          a13


      28
     ----*a8*b2
      3
b12=------------
        a13


     28*a8*b2
b11=----------
       a13


      140
     -----*a8*b2
       3
b10=-------------
         a13


     140     3
    -----*a15 *b2
     27
b9=---------------
           3
        a13


     70     2
    ----*a15 *b2
     9
b8=--------------
           2
        a13


     280     2
    -----*a15 *b2
      9
b7=---------------
           2
        a13


     70     2
    ----*a15 *b2
     9
b6=--------------
           2
        a13


     70
    ----*a15*b2
     3
b5=-------------
        a13


    14*a15*b2
b4=-----------
       a13


     14
    ----*a15*b2
     3
b3=-------------
        a13


     2
a18=---*a8
     3


     1
a17=---*a8
     3


     1
a16=---*a15
     2


     1
a14=---*a13
     2


a12=a13


     1
a11=---*a13
     2


      3      2
     ----*a13
      20
a10=-----------
        a15


a9=2*a8


    a13*a8
a7=--------
     a15


    2*a13*a8
a6=----------
      a15


    1
a5=---*a15
    2


a4=a13


    1
a3=---*a13
    2


     3      2
    ----*a13
     20
a2=-----------
       a15


Parameters

Apart from the condition that they must not vanish to give a non-trivial solution and a non-singular solution with non-vanishing denominators, the following parameters are free:
 b2,a13,a15,a8

Relevance for the application:

The solution given above tells us that the system {u_s, v_s} is a higher order symmetry for the lower order system {u_t,v_t} where u=u(t,x) is a scalar function, v=v(t,x) is a vector function of arbitrary dimension and f(..,..) is the scalar product between two such vectors:
/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\

          3          2    1
df(u,t)=(----*u  *a13  + ---*u  *a13*a15*u + u  *u *a13*a15 + u *f(v,v)*a15*a8
          20   5x         2   3x              2x  x            x

             1        2  2
          + ---*u *a15 *u  + 2*f(v ,v  )*a13*a8 + f(v,v  )*a13*a8
             2   x                x  2x                3x

          + 2*f(v,v )*a15*a8*u)/a15
                   x

                3       14         2                         2
df(u,s)=(u  *a13 *b2 + ----*u  *a13 *a15*b2*u + 14*u  *u *a13 *a15*b2
          7x            3    5x                     4x  x

             70             2           140
          + ----*u  *u  *a13 *a15*b2 + -----*u  *f(v,v)*a13*a15*a8*b2
             3    3x  2x                 9    3x

             70             2     2    280                2
          + ----*u  *a13*a15 *b2*u  + -----*u  *u *a13*a15 *b2*u
             9    3x                    9    2x  x

             560                               70    3        2
          + -----*u  *f(v,v )*a13*a15*a8*b2 + ----*u  *a13*a15 *b2
              9    2x      x                   9    x

             140                               560
          + -----*u *f(v ,v )*a13*a15*a8*b2 + -----*u *f(v,v  )*a13*a15*a8*b2
              3    x    x  x                    9    x      2x

             280               2            140        3     3
          + -----*u *f(v,v)*a15 *a8*b2*u + -----*u *a15 *b2*u
              9    x                        27    x

             140                2                         2
          + -----*f(v  ,v  )*a13 *a8*b2 + 28*f(v ,v  )*a13 *a8*b2
              3      2x  3x                     x  4x

             560                               28              2
          + -----*f(v ,v  )*a13*a15*a8*b2*u + ----*f(v,v  )*a13 *a8*b2
              9      x  2x                     3        5x

             280                              560                       2
          + -----*f(v,v  )*a13*a15*a8*b2*u + -----*f(v,v )*f(v,v)*a15*a8 *b2
              9        3x                     27        x

             280             2        2     3
          + -----*f(v,v )*a15 *a8*b2*u )/a13
              9        x

          1                                                          2
df(v,t)=(---*u  *a13*a15*v + u  *v *a13*a15 + u *v  *a13*a15 + u *a15 *u*v
          2   3x              2x  x            x  2x            x

             3          2    1                   1
          + ----*v  *a13  + ---*v  *a13*a15*u + ---*v *f(v,v)*a15*a8
             20   5x         2   3x              3   x

             1        2  2    2
          + ---*v *a15 *u  + ---*f(v,v )*a15*a8*v)/a15
             2   x            3       x

          14         2                         2
df(v,s)=(----*u  *a13 *a15*b2*v + 14*u  *v *a13 *a15*b2
          3    5x                     4x  x

             70             2           140             2
          + ----*u  *v  *a13 *a15*b2 + -----*u  *a13*a15 *b2*u*v
             3    3x  2x                 9    3x

             280                2         70             2
          + -----*u  *u *a13*a15 *b2*v + ----*u  *v  *a13 *a15*b2
              9    2x  x                  3    2x  3x

             280                2         70    2           2
          + -----*u  *v *a13*a15 *b2*u + ----*u  *v *a13*a15 *b2
              9    2x  x                  3    x   x

                         2           280                2
          + 14*u *v  *a13 *a15*b2 + -----*u *v  *a13*a15 *b2*u
                x  4x                 9    x  2x

             280               2            140        3     2            3
          + -----*u *f(v,v)*a15 *a8*b2*v + -----*u *a15 *b2*u *v + v  *a13 *b2
             27    x                         9    x                 7x

             14         2             28
          + ----*v  *a13 *a15*b2*u + ----*v  *f(v,v)*a13*a15*a8*b2
             3    5x                  9    3x

             70             2     2    112
          + ----*v  *a13*a15 *b2*u  + -----*v  *f(v,v )*a13*a15*a8*b2
             9    3x                    9    2x      x

             140                               56
          + -----*v *f(v ,v )*a13*a15*a8*b2 + ----*v *f(v,v  )*a13*a15*a8*b2
              9    x    x  x                   3    x      2x

             280               2            140        3     3
          + -----*v *f(v,v)*a15 *a8*b2*u + -----*v *a15 *b2*u
             27    x                        27    x

             280                               112
          + -----*f(v ,v  )*a13*a15*a8*b2*v + -----*f(v,v  )*a13*a15*a8*b2*v
              9      x  2x                      9        3x

             560             2               3
          + -----*f(v,v )*a15 *a8*b2*u*v)/a13
             27        x

df(u,t)=(3/20*df(u,x,5)*a13**2 + 1/2*df(u,x,3)*a13*a15*u + df(u,x,2)*df(u,x)*a13
*a15 + df(u,x)*f(v,v)*a15*a8 + 1/2*df(u,x)*a15**2*u**2 + 2*f(df(v,x),df(v,x,2))*
a13*a8 + f(v,df(v,x,3))*a13*a8 + 2*f(v,df(v,x))*a15*a8*u)/a15$

df(u,s)=(df(u,x,7)*a13**3*b2 + 14/3*df(u,x,5)*a13**2*a15*b2*u + 14*df(u,x,4)*df(
u,x)*a13**2*a15*b2 + 70/3*df(u,x,3)*df(u,x,2)*a13**2*a15*b2 + 140/9*df(u,x,3)*f(
v,v)*a13*a15*a8*b2 + 70/9*df(u,x,3)*a13*a15**2*b2*u**2 + 280/9*df(u,x,2)*df(u,x)
*a13*a15**2*b2*u + 560/9*df(u,x,2)*f(v,df(v,x))*a13*a15*a8*b2 + 70/9*df(u,x)**3*
a13*a15**2*b2 + 140/3*df(u,x)*f(df(v,x),df(v,x))*a13*a15*a8*b2 + 560/9*df(u,x)*f
(v,df(v,x,2))*a13*a15*a8*b2 + 280/9*df(u,x)*f(v,v)*a15**2*a8*b2*u + 140/27*df(u,
x)*a15**3*b2*u**3 + 140/3*f(df(v,x,2),df(v,x,3))*a13**2*a8*b2 + 28*f(df(v,x),df(
v,x,4))*a13**2*a8*b2 + 560/9*f(df(v,x),df(v,x,2))*a13*a15*a8*b2*u + 28/3*f(v,df(
v,x,5))*a13**2*a8*b2 + 280/9*f(v,df(v,x,3))*a13*a15*a8*b2*u + 560/27*f(v,df(v,x)
)*f(v,v)*a15*a8**2*b2 + 280/9*f(v,df(v,x))*a15**2*a8*b2*u**2)/a13**3$

df(v,t)=(1/2*df(u,x,3)*a13*a15*v + df(u,x,2)*df(v,x)*a13*a15 + df(u,x)*df(v,x,2)
*a13*a15 + df(u,x)*a15**2*u*v + 3/20*df(v,x,5)*a13**2 + 1/2*df(v,x,3)*a13*a15*u 
+ 1/3*df(v,x)*f(v,v)*a15*a8 + 1/2*df(v,x)*a15**2*u**2 + 2/3*f(v,df(v,x))*a15*a8*
v)/a15$

df(v,s)=(14/3*df(u,x,5)*a13**2*a15*b2*v + 14*df(u,x,4)*df(v,x)*a13**2*a15*b2 + 
70/3*df(u,x,3)*df(v,x,2)*a13**2*a15*b2 + 140/9*df(u,x,3)*a13*a15**2*b2*u*v + 280
/9*df(u,x,2)*df(u,x)*a13*a15**2*b2*v + 70/3*df(u,x,2)*df(v,x,3)*a13**2*a15*b2 + 
280/9*df(u,x,2)*df(v,x)*a13*a15**2*b2*u + 70/3*df(u,x)**2*df(v,x)*a13*a15**2*b2 
+ 14*df(u,x)*df(v,x,4)*a13**2*a15*b2 + 280/9*df(u,x)*df(v,x,2)*a13*a15**2*b2*u +
 280/27*df(u,x)*f(v,v)*a15**2*a8*b2*v + 140/9*df(u,x)*a15**3*b2*u**2*v + df(v,x,
7)*a13**3*b2 + 14/3*df(v,x,5)*a13**2*a15*b2*u + 28/9*df(v,x,3)*f(v,v)*a13*a15*a8
*b2 + 70/9*df(v,x,3)*a13*a15**2*b2*u**2 + 112/9*df(v,x,2)*f(v,df(v,x))*a13*a15*
a8*b2 + 140/9*df(v,x)*f(df(v,x),df(v,x))*a13*a15*a8*b2 + 56/3*df(v,x)*f(v,df(v,x
,2))*a13*a15*a8*b2 + 280/27*df(v,x)*f(v,v)*a15**2*a8*b2*u + 140/27*df(v,x)*a15**
3*b2*u**3 + 280/9*f(df(v,x),df(v,x,2))*a13*a15*a8*b2*v + 112/9*f(v,df(v,x,3))*
a13*a15*a8*b2*v + 560/27*f(v,df(v,x))*a15**2*a8*b2*u*v)/a13**3$