Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A General Derivation of Pointer States: Decoherence and Classicality   The purpose of the present study is to derive the pointer states of a
macroscopic system interacting with its environment, under the general
assumptions, i.e., without assuming any form of the interaction Hamiltonian.
The lowest order perturbation leads that the interaction energy shifts the
phase factors of the state vectors. For a macroscopic system, these factors are
the macroscopic quantities even for the very weak interaction. When we group
the state vector of the total system by the view point of environmental side,
the destructive interference occurs and the stationary phase approximation can
be adopted. Only the pointer states then survive and the decoherence also
occurs. The present approach is within the standard quantum mechanics as same
as the standard decoherence theory, but the meaning of the classical state is
much clear.

14
The categories of this paper are: math-ph
36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an
23
The categories of this paper are: solv-int
2
The categories of this paper are: math
8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
6
The categories of this paper are: astro-ph
25
The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
24
The categories of this paper are: dg-ga