Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ab Initio Study of 40Ca with an Importance Truncated No-Core Shell Model   We propose an importance truncation scheme for the no-core shell model, which
enables converged calculations for nuclei well beyond the p-shell. It is based
on an a priori measure for the importance of individual basis states
constructed by means of many-body perturbation theory. Only the physically
relevant states of the no-core model space are considered, which leads to a
dramatic reduction of the basis dimension. We analyze the validity and
efficiency of this truncation scheme using different realistic nucleon-nucleon
interactions and compare to conventional no-core shell model calculations for
4He and 16O. Then, we present the first converged calculations for the ground
state of 40Ca within no-core model spaces including up to
16\hbar\Omega-excitations using realistic low-momentum interactions. The scheme
is universal and can be easily applied to other quantum many-body problems.

28
The categories of this paper are: alg-geom
13
The categories of this paper are: quant-ph
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
29
The categories of this paper are: funct-an
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
27
The categories of this paper are: comp-gas
3
The categories of this paper are: physics
23
The categories of this paper are: solv-int
32
The categories of this paper are: atom-ph
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat