Browsing by Subject "Unimodality"

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    Analytic and asymptotic properties of non-symmetric Linnik's probability densities
    (1995) Erdoğan, M. Burak
    We prove that the function 1 , a 6 (0 ,2 ), ^ e R, 1 + is a characteristic function of a probability distribution if and only if ( a , 0 e P D = {{a,e) : a € (0,2), \d\ < m in (f^ , x - ^ ) (mod 27t)}. This distribution is absolutely continuous, its density is denoted by p^(x). For 0 = 0 (mod 2tt), it is symmetric and was introduced by Linnik (1953). Under another restrictions on 0 it was introduced by Laha (1960), Pillai (1990), Pakes (1992). In the work, it is proved that p^{±x) is completely monotonic on (0, oo) and is unimodal on R for any (a,0) € PD. Monotonicity properties of p^(x) with respect to 9 are studied. Expansions of p^(x) both into asymptotic series as X —»· ±oo and into conditionally convergent series in terms of log |x|, \x\^ (^ = 0 ,1 ,2 ,...) are obtained. The last series are absolutely convergent for almost all but not for all values of (a, 0) € PD. The corresponding subsets of P D are described in terms of Liouville numbers.
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    Analytic and asymptotic properties of non-symmetric Linnik's probability densities
    (1999) Erdoǧan, M.B.
    The function φθα(t) =1/1 + e-iθsgnt|t|α, α ε (0, 2), θ ε (-π, π], is a characteristic function of a probability distribution iff |θ| ≤ min(πα/2, π - πα/2). This distribution is absolutely continuous; for θ = 0 it is symmetric. The latter case was introduced by Linnik in 1953 [13] and several applications were found later. The case θ ≠ 0 was introduced by Klebanov, Maniya, and Melamed in 1984 [9], while some special cases were considered previously by Laha [12] and Pillai [18]. In 1994, Kotz, Ostrovskii and Hayfavi [10] carried out a detailed investigation of analytic and asymptotic properties of the density of the distribution for the symmetric case θ = 0. We generalize their results to the non-symmetric case θ ≠ 0. As in the symmetric case, the arithmetical nature of the parameter a plays an important role, but several new phenomena appear.