Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Representation of a complex Green function on a real basis: I. General
  Theory   When the Hamiltonian of a system is represented by a finite matrix,
constructed from a discrete basis, the matrix representation of the resolvent
covers only one branch. We show how all branches can be specified by the phase
of a complex unit of time. This permits the Hamiltonian matrix to be
constructed on a real basis; the only duty of the basis is to span the
dynamical region of space, without regard for the particular asymptotic
boundary conditions that pertain to the problem of interest.

37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
4
The categories of this paper are: cond-mat
0
The categories of this paper are: hep-ph
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
6
The categories of this paper are: astro-ph