Let X^H = {X^H(8),8∈ R^N1} and XK = {X^K(t),t ∈R^2} be two independent anisotropic Gaussian random fields with values in R^d with indices H = (H1,... ,HN1) ∈ (0, 1)^N1, K = (K1,..., KN2)∈ (0, 1)^N2, r...Let X^H = {X^H(8),8∈ R^N1} and XK = {X^K(t),t ∈R^2} be two independent anisotropic Gaussian random fields with values in R^d with indices H = (H1,... ,HN1) ∈ (0, 1)^N1, K = (K1,..., KN2)∈ (0, 1)^N2, respectively. Existence of intersections of the sample paths of XH and XK is studied. More generally, let E1 R^N1, E2 R^N2 and F R^d be Borel sets. A necessary condition and a sufficient condition for P{(X^H(E1) ∩ X^K(E2)) ∩ F ≠ Ф} 〉 0 in terms of the Bessel-Riesz type capacity and Hausdorff measure of E1 x E2 x F in the metric space (R^N1+N2+d, ρ) are proved, whereρ is a metric defined in terms of H and K. These results are applicable to solutions of stochastic heat equations driven by space-time Gaussian noise and fractional Brownian sheets.展开更多
基金supported by Zhejiang Provincial Natural Science Foundation of China(Grant No. Y6100663)National Science Foundation of US (Grant No. DMS-1006903)
文摘Let X^H = {X^H(8),8∈ R^N1} and XK = {X^K(t),t ∈R^2} be two independent anisotropic Gaussian random fields with values in R^d with indices H = (H1,... ,HN1) ∈ (0, 1)^N1, K = (K1,..., KN2)∈ (0, 1)^N2, respectively. Existence of intersections of the sample paths of XH and XK is studied. More generally, let E1 R^N1, E2 R^N2 and F R^d be Borel sets. A necessary condition and a sufficient condition for P{(X^H(E1) ∩ X^K(E2)) ∩ F ≠ Ф} 〉 0 in terms of the Bessel-Riesz type capacity and Hausdorff measure of E1 x E2 x F in the metric space (R^N1+N2+d, ρ) are proved, whereρ is a metric defined in terms of H and K. These results are applicable to solutions of stochastic heat equations driven by space-time Gaussian noise and fractional Brownian sheets.