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Carleman's condition

In mathematics, particularly, in analysis, Carleman's condition gives a sufficient condition for the determinacy of the moment problem. That is, if a measure satisfies Carleman's condition, there is no other measure having the same moments as The condition was discovered by Torsten Carleman in 1922.

Hamburger moment problem
For the Hamburger moment problem (the moment problem on the whole real line), the theorem states the following: Let \mu be a measure on \R such that all the moments m_n = \int_{-\infty}^{+\infty} x^n \, d\mu(x)~, \quad n = 0,1,2,\cdots are finite. If \sum_{n=1}^\infty m_{2n}^{-\frac{1}{2n}} = + \infty, then the moment problem for (m_n) is determinate; that is, \mu is the only measure on \R with (m_n) as its sequence of moments. ==Stieltjes moment problem==
Stieltjes moment problem
For the Stieltjes moment problem, the sufficient condition for determinacy is \sum_{n=1}^\infty m_{n}^{-\frac{1}{2n}} = + \infty. ==Generalized Carleman's condition==
Generalized Carleman's condition
In Nasiraee et al. showed that, despite previous assumptions, when the integrand is an arbitrary function, Carleman's condition is not sufficient, as demonstrated by a counter-example. In fact, the example violates the bijection, i.e. determinacy, property in the probability sum theorem. When the integrand is an arbitrary function, they further establish a sufficient condition for the determinacy of the moment problem, referred to as the ''generalized Carleman's condition''. ==Notes==
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