Page 48 - swp0000.dvi
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(20)   (20)   (20)  (20)        (20)
                       The coefficients of the harmonic modes              3    1   2   1   and  2
                   are given by



                                                            (20)    1
                                                           3   =    
                                                                    2


                                                       ³                               ´
                                        (20)      0   2                  (20)  3
                                       1  =              (2  + ) −  3     
                                                3
                                                   2 2
                                                 
                                                    
                                                             ³                   ´
                                              (20)
                                                       
                                                                             2
                                                                2
                                             2  =              −  3 (20)    
                                                      2
                                                         2
                                                       
                                                         
                                                 ∙         2                          2       2         ¸
                                         2
                                                 0  (2     0  +    0  +3 0  )
                        (20)
                       1  = ¡          0   ¢                  2              2 2              −  3 (20)  
                                       2
                                  0  − 3 0              (   0 − 3 0 )
                                       
                   and
                                                          2             2       2
                                      (20)     (   0 ) [  (   0  +3 0  )+6 0 ]
                                          =      ¡               ¢
                                      2
                                                                                      2 2
                                                                      2
                                                           2
                                                      0  − 3 0 (    0 − 3 0  )
                                                           
                                                        0     (20)
                                               −¡                ¢ 3   
                                                          2
                                                     0  − 3 0
                                                          
                   where
                                               ⎡                                      ⎤
                                                                  3
                                                     0   0     0 2
                                                      2 −   2 +       3 (2  + )
                                                                   2 2
                                               ⎢                                   ⎥
                                                                  2
                                                     3 2
                                                         3
                                                                        2
                                       1 = − ⎣       (   0  +3 0  +2     0 )  ⎦ 
                                                  +     0
                                                              2
                                                                                2 2
                                                                     2
                                                      (   0   −3 0)(    0 −3 0  )
                   and
                                                                 2               2
                                                                                2
                                           0           0     0             0
                                                                
                                      2 =    +(1 − )      −         − ¡                ¢ 
                                                                                  2
                                                              2       0  − 3 0
                                                                                 
                   Finally, the first harmonic ( =1), of the third order perturbed quantities
                   gives the following NLS equation
                                                 (1)      2 (1)
                                                                ¯   ¯ 2  (1)
                                                1  +      1  +  ¯ ¯    1  =0                     (2.16)
                                                                    ¯ (1)¯
                                                                      1
                                                         2
                   The coefficient of dispersion term,  is given by
                                                               36
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