Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Conditional probabilities of measurements, quantum time and the Wigner's
  friend case   Considering a minimal number of assumptions and in the context of the
timeless formalism, conditional probabilities are derived for subsequent
measurements in the non-relativistic regime. Only unitary transformations are
considered with detection processes described by generalized measurements
(POVM). One-time conditional probabilities are unambiguously derived via the
Gleason-Bush theorem, including for puzzling cases like the Wigner's friend
scenario where their form underlines the relativity aspect of measurements. No
paradoxical situations emerge and the roles of Wigner and Wigner can be seen by
his friend as being in a superposition.

7
The categories of this paper are: hep-th
11
The categories of this paper are: hep-lat
0
The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
19
The categories of this paper are: eess
14
The categories of this paper are: math-ph
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol
12
The categories of this paper are: nucl-th
26
The categories of this paper are: bayes-an
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ