Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Bound states and E_8 symmetry effects in perturbed quantum Ising chains   In a recent experiment on CoNb_2O_6, Coldea et al. [Science 327, 177 (2010)]
found for the first time experimental evidence of the exceptional Lie algebra
E_8. The emergence of this symmetry was theoretically predicted long ago for
the transverse quantum Ising chain in the presence of a weak longitudinal
field. We consider an accurate microscopic model of CoNb_2O_6 incorporating
additional couplings and calculate numerically the dynamical structure function
using a recently developed matrix-product-state method. The excitation spectra
show bound states characteristic of the weakly broken E_8 symmetry. We compare
the observed bound state signatures in this model to those found in the
transverse Ising chain in a longitudinal field and to experimental data.

22
The categories of this paper are: chao-dyn
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
8
The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
33
The categories of this paper are: plasm-ph
15
The categories of this paper are: nucl-ex
17
The categories of this paper are: q-fin
7
The categories of this paper are: hep-th
27
The categories of this paper are: comp-gas
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin