Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Group theoretical foundations of the Quantum Theory of an interacting
  particle   {We point out some obstacles raised by the lost of symmetry against the
extension to the case of an interacting particle of the approach that {\sl
deductively} establishes the Quantum Theory of a free particle according to the
group theoretical methods worked out by Bargmann, Mackey and Wigner. Then we
develop an approach which overcomes these difficulties in the non relativistic
case. According to our approach the different specific forms of the wave
equation of an interacting particle are implied by particular first order
invariance properties that characterize the interaction with respect to
specific sub-groups of galileian transformations. Moreover, the possibility of
yet unknown forms of the wave equation is left open.

21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
3
The categories of this paper are: physics
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
23
The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom