Consistent monitoring of quantum fluctuations
Xiangyu Cao
Phys. Rev. A 114, L010201 (2026) - Published 6 July, 2026
This Letter considers whether fluctuations of extensive quantities in many-body systems can be consistently monitored, namely, whether measurements can be performed without disturbing future outcome distribution. The answer turns out to be “no” in a large class of situations, and the amount of disturbance can be exactly calculated in terms of linear response quantities.




















