Agents governed by quantum mechanics can use it intersubjectively and consistently

Abstract

Following Frauchiger and Renner's discovery of a conflict between quantum mechanics and certain commonsense reasoning axioms, much work has gone into finding alternative axiomatizations that can avoid the conflict. However, this body of work is largely based on specific interpretations of quantum mechanics, and at times employs specialized formalism that may be inaccessible to mainstream quantum information experts. Taking an interpretation-agnostic approach, we propose a simple operational principle called superpositional solipsism to aid rational agents in making situational inferences. We show that the principle leads to sound inferences in all operationallyrelevant instances. Along the way, we discuss certain subtleties about the Frauchiger-Renner result that may have gone hithertofore unnoticed.

Consistency in the description of quantum measurement: Quantum theory can consistently describe the use of itself

“…Many have made suggestions for how the FR paradox can be avoided which are similar in spirit. Closely related are the discussion of "stable versus relative facts" by Di Biagio and Rovelli [15], the principle of "superpositional solipsism" of Narasimhachar [16], and the criteron of Elouard et al that observers are only observers when they can store the measurement result in some degree of freedom until the end of the experiment [17]. Elouard et al also point out the relevance of the quantum eraser to the discussion of FR paradox, as do Żukowski and Markiewicz [18].…”

Testing quantum theory with thought experiments

“…Any interpretation that dismisses C should thus substitute it with other means for agents to compare their individual views. While this problem has been largely ignored until recently (but see [47,77]), one can be optimistic that future research, inspired by (real or thought) experiments, will soon shed more light on it.…”