Page 119 - Special Topic Session (STS) - Volume 3
P. 119

STS518 B.H. Jasiulis G. et al.
            Definition 2.
            A  measure   є   is  said  to  be  infinitely  divisible  with  respect  to  the
                             +
            generalized convolution ⋄ (-⋄ infinitely decomposable) in the algebra ( ,⋄) if
                                                                                  +
            for every  ⋄ є  there exists a probability measure   є   such that
                                                               
                                                                    +
                                           =   ⋄ .
                                                

            One of the most important examples of ⋄-infinitely divisible distribution is ⋄-
            compound  Poisson  measure  ⋄ ()  defined  in  [5,  9,  10,  11].  In  next
            example  the  Poisson  probability  measure  in  the  Kendall  generalized
            convolution algebra is presented.

            Example 4.


            It  is  worth  to  notice  that  Poisson  measures  with  respect  to  generalized
            convolutions are not strictly discrete and have usually a continuous part. In [1]
            we proved that the last measure at the above convex linear combination is
            stable in the Kendall convolution algebra in the sense of Definition 3.

            Definition 3.
            Let  є  . We  say  that  λ  is  stable  in  the  generalized  convolution  algebra
                     +
            ( ,⋄), if for all a, b ≥ 0 there exists c ≥ 0 such that
               +


            Similarly  to  the  classical  theory  stable  distributions  in  the  generalized
            convolutions sense are ⋄ - infinitely divisible.  The generalized characteristic
                                                                        
            function of ⋄ - infinitely divisible distribution is exponent of   for some   >
             0.  For  every  generalized  convolution ⋄ on   there  exists  a  constant (⋄),
                                                         +
            called a characteristic exponent, such that for every  є (0, (⋄)] there exists
            a  measure   є   with  the  ⋄-generalized  characteristic  function   (t) =
                             +
                                                                                 
                         
                   p
             exp{−t } if   <  ∞ and   (t) =  [0,1] (t) otherwise. For example (⋄) =  2
                                       
            for classical convolution and ( ) =   for the case of Kendall convolution.
                                            
            Moreover, the set of all ⋄ - stable measures coincides with the set {   :    >
                                                                              
                                                                                 
             0,  є (0, (⋄)]}.










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