Reply to "Comment on `Weak values and the past of a quantum particle' ''

Abstract

We here reply to a recent comment by Vaidman [\href{https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.5.048001}{Phys. Rev. Res. 5, 048001 (2023)}] on our paper [\href{https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.5.023048}{Phys. Rev. Res. 5, 023048 (2023)}]. In his Comment, Vaidman first admits that he is just defining (assuming) the weak trace gives the presence of a particle -- however, in this case, he should use a term other than presence, as this already has a separate, intuitive meaning other than ``where a weak trace is''. Despite this admission, Vaidman then goes on to argue for this definition by appeal to ideas around an objectively-existing idea of presence. We show these appeals rely on their own conclusion -- that there is always a matter of fact about the location of a quantum particle.