Mixed volume of infinite-dimensional convex compact sets

Dospolova M. K. Mixed volume of infinite-dimensional convex compact sets. Let $K$ be a convex compact $GB$-subset of a separable Hilbert space $H$. Denote by $\mathrm{Spec}_k K$ the set $\{(\xi_1(h), \ldots, \xi_k(h))\colon h\in K\}\subset \mathbb{R}^k,$ where $\xi_1, \ldots, \xi_k$ are independent copies of the isonormal Gaussian process. Tsirelson showed that in this case the intrinsic volumes of $K$ satisfy the relation
\begin{equation*} V_k(K)= \frac{(2\pi)^{k/2}}{k!\kappa_k} \mathbf{E} \mathrm{Vol}_k(\mathrm{Spec}_k K). \end{equation*}
Here, $\mathbf{E} \ \mathrm{Vol}_k(\mathrm{Spec}_k K)$ is the mean volume of $\mathrm{Spec}_k K$ and $\kappa_k$ is the volume of the $k$-dimensional unit ball.
In this work, we generalize Tsirelson's theorem to the case of mixed volumes of infinite-dimensional convex compact $GB$-subsets of $H$, first introducing the notion of mixed volume for infinite-dimensional convex subsets of $H$.
Moreover, using the obtained result we compute the mixed volume of the closed convex hulls of two orthogonal Wiener spirals.