Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The 'Delayed Choice Quantum Eraser' Neither Erases Nor Delays   It is demonstrated that 'quantum eraser' (QE) experiments do not erase any
information. Nor do they demonstrate retrocausation or 'temporal nonlocality'
in their 'delayed choice' form, beyond standard EPR correlations. It is shown
that the erroneous erasure claims arise from assuming that the improper mixed
state of the signal photon physically prefers either the 'which way' or 'both
ways' basis, when no such preference is warranted. The latter point is
illustrated through comparison of the QE spatial state space with the spin-1/2
space of particles in the EPR-spin experiment.

17
The categories of this paper are: q-fin
9
The categories of this paper are: nlin
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
2
The categories of this paper are: math
3
The categories of this paper are: physics
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol