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作者:ASMUSSEN, S
摘要:The distributions of random walk quantities like ascending ladder heights and the maximum are shown to be phase-type provided that the generic random walk increment X has difference structure X = U - T with U phase-type, or the one-sided assumption of X+ being phase-type is imposed. As a corollary, it follows that the stationary waiting time in a GI/PH/1 queue with phase-type service times is again phase-type. The phase-type representations are characterized in terms of the intensity matrix Q ...
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作者:PEDDADA, SD
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作者:BERTOIN, J; LEJAN, Y
摘要:Let X be a Hunt process starting from a regular recurrent point 0 and nu a smooth probability measure on the state space. We show that T = inf{s: A(s) > L(s)}, where A is the continuous additive functional associated to nu and L the local time at 0, solves the Skorokhod problem for nu, that is, X(T) has law-nu. We construct another solution which minimizes E0(B(S)) among all the solutions S of the Skorokhod problem, where B is any positive continuous additive functional. The special case where...
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作者:JUREK, ZJ
作者单位:University of Wroclaw
摘要:A notion of U-exponents of a probability measure on a linear space is introduced. These are bounded linear operators and it is shown that the set of all U-exponents forms a Lie wedge for full measures on finite-dimensional spaces. This allows the construction of U-exponents commuting with the symmetry group of a measure in question. Then the set of all commuting exponents is described and elliptically symmetric measures are characterized in terms of their Fourier transforms. Also, self-decompo...
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作者:BASAK, GK; BHATTACHARYA, RN
作者单位:Indiana University System; Indiana University Bloomington
摘要:A verifiable criterion is derived for the stability in distribution of singular diffusions, that is, for the weak convergence of the transition probability p(t; x, dy), as t --> infinity, to a unique invariant probability. For this we establish the following: (i) tightness of {p(t; x, dy): t greater-than-or-equal-to 0}; and (ii) asymptotic flatness of the stochastic flow. When specialized to highly nonradial nonsingular diffusions the results here are often applicable where Has'minskii's well-...
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作者:LYONS, R; PEMANTLE, R
作者单位:University of Wisconsin System; University of Wisconsin Madison; Stanford University; University of California System; University of California Berkeley
摘要:We show that the transience or recurrence of a random walk in certain random environments on an arbitrary infinite locally finite tree is determined by the branching number of the tree, which is a measure of the average number of branches per vertex. This generalizes and unifies previous work of the authors. It also shows that the point of phase transition for edge-reinforced random walk is likewise determined by the branching number of the tree. Finally, we show that the branching number dete...
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作者:DINWOODIE, IH; ZABELL, SL
摘要:Say that a family (P(theta)n: theta is-an-element-of THETA) of sequences of probability measures is exponentially continuous if whenever theta(n) --> theta, the sequence {P(theta-n)n} satisfies a large deviation principle with rate function lambda(theta). If THETA is compact and {P(theta)n} is exponentially continuous, then the mixture P(n)(A) =: integral-THETA P(theta)n(A)d-mu(theta) satisfies a large deviation principle with rate function lambda(x) =: inf{lambda(theta)(x): theta is-an-elemen...
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作者:FREIDLIN, MI; WENTZELL, AD
作者单位:Lomonosov Moscow State University
摘要:We consider semilinear parabolic PDE's with fast oscillating boundary conditions. The central limit theorem and limit theorems for probabilities of large deviations for the solutions of such problems are proved.
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作者:MELFI, VF
作者单位:University of Michigan System; University of Michigan
摘要:An analogue of the Lai-Siegmund nonlinear renewal theorem is proved for processes of the form S(n) + xi(n), where {S(n)} is a Markov random walk. Specifically, Y0, Y1,... is a Markov chain with complete separable metric state space; X1, X2,... is a sequence of random variables such that the distribution of X(i) given {Y(j), j greater-than-or-equal-to 0} and {X(j), j not-equal i} depends only on Y(i-1) and Y(i); S(n) = X1 + ... +X(n); and {xi(n)} is slowly changing, in a sense to be made precis...
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作者:ALEXANDER, KS; KALIKOW, SA
摘要:Given a finite alphabet, there is an inductive method for constructing a stationary measure on doubly infinite words from this alphabet. This construction can be randomized; the main focus here is on a particular uniform randomization which intuitively corresponds to the idea of choosing a generic stationary process. It is shown that with probability 1, the random stationary process has zero entropy and gives positive probability to every periodic infinite word.