Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Effective field theory of resonant 2-level atoms   The phenomenological two-level atom is re-analysed using the methods of
effective field theory. By presenting the Dicke-Jaynes-Cummings model in real
space, an exact diagonalization is accomplished going beyond the rotating wave
approximation. The meaning of the symmetries and conserved quantities in the
theory is discussed and the model is related to non-equilibrium field theory.
The structure of the solution raises a question about the rotating wave
approximation in quantum mechanics.

37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph
12
The categories of this paper are: nucl-th
15
The categories of this paper are: nucl-ex
27
The categories of this paper are: comp-gas
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph
17
The categories of this paper are: q-fin
22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin
4
The categories of this paper are: cond-mat