Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: No relation for Wigner's friend   We argue that Wigner's friend thought experiment does not support observer
dependence of quantum states. An analysis in terms of history vectors suggests
that quantum collapse is to be understood as collapse of histories rather than
collapse of states.

20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
23
The categories of this paper are: solv-int
1
The categories of this paper are: cs
6
The categories of this paper are: astro-ph
9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math
36
The categories of this paper are: cmp-lg
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
18
The categories of this paper are: econ