- Stieltjes moment problem
In
mathematics , the Stieltjesmoment problem , named afterThomas Joannes Stieltjes , seeksnecessary and sufficient conditions that a sequence { μ"n", : "n" = 0, 1, 2, ... } be of the form:mu_n=int_0^infty x^n,dF(x),
for some nondecreasing function "F".
The essential difference between this and other well-known
moment problem s is that this is on a half-line[ 0, ∞) , whereas in theHausdorff moment problem one considers a bounded interval [0, 1] , and in theHamburger moment problem one considers the whole line (−∞, ∞).Let
:Delta_n=left [egin{matrix}1 & mu_1 & mu_2 & cdots & mu_{n} \mu_1 & mu_2 & mu_3 & cdots & mu_{n+1} \mu_2& mu_3 & mu_4 & cdots & mu_{n+2} \vdots & vdots & vdots & ddots & vdots \mu_{n} & mu_{n+1} & mu_{n+2} & cdots & mu_{2n}end{matrix} ight] .
and
:Delta_n^{(1)}=left [egin{matrix}mu_1 & mu_2 & mu_3 & cdots & mu_{n+1} \mu_2 & mu_3 & mu_4 & cdots & mu_{n+2} \mu_3 & mu_4 & mu_5 & cdots & mu_{n+3} \vdots & vdots & vdots & ddots & vdots \mu_{n+1} & mu_{n+2} & mu_{n+3} & cdots & mu_{2n+1}end{matrix} ight] .
Then { μ"n" : "n" = 1, 2, 3, ... } is a moment sequence of some probability distribution on 0,infty) with infinite support if and only if for all "n", both
:det(Delta_n) > 0 mathrm{and} detleft(Delta_n^{(1)} ight) > 0.
{ μ"n" : "n" = 1, 2, 3, ... } is a moment sequence of some probability distribution on 0,infty) with finite support of size "m" if and only if for all n leq m, both
:det(Delta_n) > 0 mathrm{and} detleft(Delta_n^{(1)} ight) > 0.
and for all larger n
:det(Delta_n) = 0 mathrm{and} detleft(Delta_n^{(1)} ight) = 0.The solution is unique if there are constants "C" and "D" such that for all "n", |μ"n"|≤ "CD""n""(2n)"! harv|Reed|Simon|1975|p=341.
References
*citation|first=Michael|last=Reed|first2=Barry|last2=Simon|title=Fourier Analysis, Self-Adjointness|year=1975|ISBN=0-12-585002-6|series=Methods of modern mathematical physics|volume=2|publisher=Academic Press|page= 341 (exercise 25)
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