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Simple method of obtaining estimates in the invariance principle. (English) Zbl 0637.60010

Probability theory and mathematical statistics, Proc. 5th Jap.-USSR Symp., Kyoto/Jap. 1986, Lect. Notes Math. 1299, 430-443 (1988).
[For the entire collection see Zbl 0626.00026.]
Let \(S=S(t)\) and \(W=W(t)\) be random broken lines, i.e. \(S(t_ k)=X_ 1+...+X_ k\) and \(W(t_ k)=Y_ 1+...+Y_ k\) where \(0<t_ 1<...<t_ n=1\). Suppose that conditional means and conditional covariance operators of the B-valued random variables \(X_ 1,...,X_ n\) are non-random and coincide with those of the independent random variables \(Y_ 1,...,Y_ n\). In this case, under some assumptions on the Banach space B, the inequality \[ P(S\in A)-P(W\in A^ r)=C r^{- 3}\sum^{n}_{k=1}(E| X_ k|^ 3+E| Y_ k|^ 3) \] is true for any Borel set A and any real \(r>0\) where \(A^ r\) is in some sense an r-neighbourhood of the set A.
This result is proved by a special smoothing inequality which allows us to change consequently the random variables \(X_ n,X_{n-1},...,X_ 2,X_ 1\) to the variables \(Y_ n,Y_{n-1},...,Y_ 2,Y_ 1\) in the definition of the process S.
Reviewer: A.I.Sakhanenko

MSC:

60B12 Limit theorems for vector-valued random variables (infinite-dimensional case)
60F17 Functional limit theorems; invariance principles
60E15 Inequalities; stochastic orderings

Citations:

Zbl 0626.00026