Curves with equal intensity of upcrossing of a bivariate Gaussian process (Q1061414)

Let \(Z_ t=(z_{1t},z_{2t})\) be a bivariate stationary Gaussian process with real components and zero mean; let \(\Gamma\) be a surface given by the equation \(\Gamma (x)=0\), \(x\in R^ 2\); \(\mu\) (B) the intensity of exits of the process \(Z_ t\) through the set B, \(B\subset \Gamma\). The existence of the curves \(\Gamma_ c\) where the density of intensity is the constant \((\mu (d\Gamma (x))=c)\) is investigated.