Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Benchmarking the variational cluster approach by means of the
  one-dimensional Bose-Hubbard model   Convergence properties of the variational cluster approach with respect to
the variational parameter space, cluster size, and boundary conditions of the
reference system are investigated and discussed for bosonic many-body systems.
Specifically, the variational cluster approach is applied to the
one-dimensional Bose-Hubbard model, which exhibits a quantum phase transition
from Mott to superfluid phase. In order to benchmark the variational cluster
approach, results for the phase boundary delimiting the first Mott lobe are
compared with essentially exact density matrix renormalization group data.
Furthermore, static quantities, such as the ground state energy and the
one-particle density matrix are compared with high-order strong coupling
perturbation theory results. For reference systems with open boundary
conditions the variational parameter space is extended by an additional
variational parameter which allows for a more uniform particle density on the
reference system and thus drastically improves the results. It turns out that
the variational cluster approach yields accurate results with relatively low
computational effort for both spectral as well as static properties of the
one-dimensional Bose-Hubbard model, even at the tip of the first Mott lobe
where correlation effects are most pronounced.

23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
16
The categories of this paper are: stat
32
The categories of this paper are: atom-ph
3
The categories of this paper are: physics
21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
0
The categories of this paper are: hep-ph