Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum many-body effects on Rydberg excitons in cuprous oxide   We investigate quantum many-body effects on Rydberg excitons in cuprous oxide
induced by the surrounding electron-hole plasma. Line shifts and widths are
calculated by full diagonalisation of the plasma Hamiltonian and compared to
results in first order perturbation theory, and the oscillator strength of the
exciton lines is analysed.

29
The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
36
The categories of this paper are: cmp-lg
5
The categories of this paper are: gr-qc
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
22
The categories of this paper are: chao-dyn
23
The categories of this paper are: solv-int
6
The categories of this paper are: astro-ph
2
The categories of this paper are: math
24
The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph
27
The categories of this paper are: comp-gas
20
The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an