Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Gaussian Dynamics is Classical Dynamics   A direct comparison of quantum and classical dynamical systems can be
accomplished through the use of distribution functions. This is useful for both
fundamental investigations such as the nature of the quantum-classical
transition as well as for applications such as quantum feedback control. By
affording a clear separation between kinematical and dynamical quantum effects,
the Wigner distribution is particularly valuable in this regard. Here we
discuss some consequences of the fact that when closed-system classical and
quantum dynamics are treated in Gaussian approximation, they are in fact
identical. Thus, it follows that several results in the so-called `semiquantum'
chaos actually arise from approximating the classical, and not the quantum
dynamics. (Similarly, opposing claims of quantum suppression of chaos are also
suspect.) As a simple byproduct of the analysis we are able to show how the
Lyapunov exponent appears in the language of phase space distributions in a way
that clearly underlines the difference between quantum and classical dynamical
situations. We also informally discuss some aspects of approximations that go
beyond the Gaussian approximation, such as the issue of when quantum nonlinear
dynamical corrections become important compared to nonlinear classical
corrections.

34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
22
The categories of this paper are: chao-dyn
15
The categories of this paper are: nucl-ex
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin