Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Decoherence of Phase Space Histories   In choosing a family of histories for a system, it is often convenient to
choose a succession of locations in phase space, rather than configuration
space, for comparison to classical histories. Although there are no good
projections onto phase space, several approximate projections have been used in
the past; three of these are examined in this paper. Expressions are derived
for the probabilities of histories containing arbitrary numbers of projections
onto phase space, and the conditions for the decoherence of these histories are
studied.

11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
4
The categories of this paper are: cond-mat
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph