Skew-symmetric functions on the hyperboloid and quantum measures (Q2365438)

Let \(H\) be a Krein space with an indefinite metric \([. , .]\) and let \({\mathcal P}\) be the system of all \(J\)-projections, i.e., the set of all \(p:H\to H\), \(p^2=p\) and \([px,y] = [x,py]\), \(x,y\in H\). The paper characterizes measures on \({\mathcal P}\), and the problem of extendibility of measures is treated.