A simple proof of the support theorem for diffusion processes
The proof that H¹(δ) and H¹(δ²) are not isomorphic is simplified. This is done by giving a new and simple proof to a martingale inequality of J. Bourgain.
In this paper we obtain a strong invariance principle for negatively associated random fields, under the assumptions that the field has a finite th moment and the covariance coefficient exponentially decreases to . The main tools are the Berkes-Morrow multi-parameter blocking technique and the Csörgő-Révész quantile transform method.
Let be a second-order stationary random field on Z². Let ℳ(L) be the linear span of , and ℳ(RN) the linear span of . Spectral criteria are given for the condition , where is the cosine of the angle between ℳ(L) and .
The Riesz transforms of a positive singular measure satisfy the weak type inequalitywhere denotes Lebesgue measure and is a positive constant only depending on .