Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Super-shell structure in harmonically trapped fermionic gases and its
  semi-classical interpretation   It was recently shown in self-consistent Hartree-Fock calculations that a
harmonically trapped dilute gas of fermionic atoms with a repulsive two-body
interaction exhibits a pronounced {\it super-shell} structure: the shell
fillings due to the spherical harmonic trapping potential are modulated by a
beat mode. This changes the ``magic numbers'' occurring between the beat nodes
by half a period. The length and amplitude of the beating mode depends on the
strength of the interaction. We give a qualitative interpretation of the beat
structure in terms of a semiclassical trace formula that uniformly describes
the symmetry breaking U(3) $\to$ SO(3) in a 3D harmonic oscillator potential
perturbed by an anharmonic term $\propto r^4$ with arbitrary strength. We show
that at low Fermi energies (or particle numbers), the beating gross-shell
structure of this system is dominated solely by the two-fold degenerate
circular and (diametrically) pendulating orbits.

29
The categories of this paper are: funct-an
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
17
The categories of this paper are: q-fin
34
The categories of this paper are: chem-ph
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
24
The categories of this paper are: dg-ga
12
The categories of this paper are: nucl-th