Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum theory of preparation and measurement   The conventional postulate for the probabilistic interpretation of quantum
mechanics is asymmetric in preparation and measurement, making retrodiction
reliant on inference by use of Bayes' theorem. Here, a more fundamental
symmetric postulate is presented, from which both predictive and retrodictive
probabilities emerge immediately, even where measurement devices more general
than those usually considered are involved. It is shown that the new postulate
is perfectly consistent with the conventional postulate.

31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
6
The categories of this paper are: astro-ph
32
The categories of this paper are: atom-ph
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
4
The categories of this paper are: cond-mat
0
The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
2
The categories of this paper are: math