Page 97 - Determinants and Their Applications in Mathematical Physics
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82   4. Particular Determinants

          Hence,
                                   WW =[α rs ] n ,
          where
                                   n
                                      (r−1)(t−1)−(t−1)(s−1)
                            α rs =   ω
                                  t=1
                                   n
                                      (t−1)(r−s)
                                =    ω        ,
                                  t=1
                            α rr = n.                               (4.4.14)
          Put k = r − s, s  = r. Then, referring to (4.4.6),

                                 n

                           α rs =  ω (t−1)k  (ω = ω = ω k )
                                              k
                                                   k
                                                   1
                                t=1
                                 n
                                     t−1
                              =    ω
                                     k
                                t=1
                              =0,     s  = r.                       (4.4.15)
          Hence,
                                     [α rs ]= nI,
                                     WW = nI.
          The lemma follows.
            The n generalized hyperbolic functions H r ,1 ≤ r ≤ n, of the (n − 1)
          independent variables x r ,1 ≤ r ≤ n−1, are defined by the matrix equation
                                         1
                                     H =   WE,                      (4.4.16)
                                         n
          where H and E are column vectors defined as follows:

                                               ,
                                              T
                         H = H 1 H 2 H 3 ...H n

                                               ,
                                             T
                          E = E 1 E 2 E 3 ...E n

                                  n−1

                         E r = exp    ω (r−1)t x t ,  1 ≤ r ≤ n.    (4.4.17)
                                   t=1
          Lemma 4.19.
                                      n

                                        E r =1.
                                     r=1
          Proof. Referring to (4.4.15),
                                           n−1

                            n       n

                               E r =   exp     ω  (r−1)t  x t
                           r=1      r=1    t=1
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