Space and time averaged quantum stress tensor fluctuations

We extend previous work on the numerical diagonalization of quantum stress tensor operators in Minkowski vacuum state, which considered averaged a finite time interval, to spacetime region. Since real experiments occur over volumes and durations, physically meaningful fluctuations may be obtained from by compactly supported sampling functions space time. The direct diagonalization, via Bogoliubov transformation, gives eigenvalues probabilities measuring those underlying probability distribution can constructed. For normal-ordered square derivative massless scalar field spherical cavity with degrees freedom, analysis tails these distributions confirms results based analytical treatment high moments. find that large is reduced when spatial averaging included, but tail still decreases more slowly than exponentially as magnitude measured increases, suggesting not always subdominant thermal opening up possibility experimental observation under right conditions.