Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Hubbard dimer within the Green's function equation of motion
  approach   We consider a formulation of the equation of motion technique for Green's
function in which the unknown averages are computed by solving a linear system.
This linear system appears solvable for all finite temperatures, but depending
on the system parameters the condition number can be very large, making the
solution numerically unfeasible at low temperatures. In the example that we
consider, the Hubbard dimer, we can get rid of this problem by making use of
total spin as a good quantum number.

19
The categories of this paper are: eess
27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
5
The categories of this paper are: gr-qc
32
The categories of this paper are: atom-ph
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
13
The categories of this paper are: quant-ph