Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Massless scalar free Field in 1+1 dimensions I: Weyl algebras Products
  and Superselection Sectors   This is the first of two papers on the superselection sectors of the
conformal model in the title, in a time zero formulation. A classification of
the sectors of the net of observables as restrictions of solitonic (twisted)
and non-solitonic (untwisted) sector automorphisms of proper extensions of the
observable net is given. All of them are implemented by the elements of a field
net in a non-regular vacuum representation and the existence of a global
compact Abelian gauge group is proved. A non-trivial center in the fixed-point
net of this gauge group appears, but in an unphysical representation and
reducing to the identity in the physical one. The completeness of the described
superselection structure, to which the second paper is devoted, is shown in
terms of Roberts' net cohomology. Some general features of physical field
models defined by twisted cross products of Weyl algebras in non-regular
representations are also presented.

31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph