Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Revisiting Hardy's Paradox: Counterfactual Statements, Real
  Measurements, Entanglement and Weak Values   Classical-realistic analysis of entangled systems have lead to retrodiction
paradoxes, which ordinarily have been dismissed on the grounds of
counter-factuality. Instead, we claim that such paradoxes point to a deeper
logical structure inherent to quantum mechanics, which is naturally described
in the language of weak values, and which is accessible experimentally via weak
measurements. Using as an illustration, a gedanken-experiment due to
Hardy\cite{hardy}, we show that there is in fact an exact numerical coincidence
between a) a pair of classically contradictory assertions about the locations
of an electron and a positron, and b) the results of weak measurements of their
location. The internal consistency of these results is due to the novel way by
which quantum mechanics "resolves" the paradox: first, by allowing for two
distinguishable manifestations of how the electron and positron can be at the
same location: either as single particles or as a pair; and secondly, by
allowing these properties to take either sign. In particular, we discuss the
experimental meaning of a {\em negative} number of electron-positron pairs.

12
The categories of this paper are: nucl-th
17
The categories of this paper are: q-fin
4
The categories of this paper are: cond-mat
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics