Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electrons in an eccentric background field   We present a description of electrons propagating in an elliptically
polarised plane wave background which includes circular and linear
polarisations as special cases. We calculate to all orders in the background
field the two point function and relate it to various expressions found in the
literature. The background field induced mass shift of the electron is shown to
be polarisation independent in the full elliptic class. The matrix nature of
this mass shift in the fermionic theory is discussed. The extent to which a
momentum space description is possible for this system is clarified.

34
The categories of this paper are: chem-ph
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
21
The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th
5
The categories of this paper are: gr-qc
12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph