Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Localisation of a wave-function by superposition of different histories   Quantum state diffusion shows how stochastic interaction with the environment
may cause localisation of the wave-function, and thereby demonstrates that
quantum mechanics need not invoke a separate axiom of measurement to explain
the emergence of the classical world. It has not been clear whether quantum
state diffusion requires some new physics. We set up an explicit numerical
calculation of the evolution of the wave-function of a two-state system under
interaction using only the physics explicitly contained in quantum mechanics
without an axiom of measurement. The wave-function does indeed localise, as
proposed by quantum state diffusion, on eigenstates of the perturbation. The
mechanism appears to be the superposition of histories evolving under different
Hamiltonians.

29
The categories of this paper are: funct-an
5
The categories of this paper are: gr-qc
11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con
17
The categories of this paper are: q-fin
25
The categories of this paper are: patt-sol
14
The categories of this paper are: math-ph
18
The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio