Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Path integral Monte Carlo determination of the fourth-order virial
  coefficient for unitary two-component Fermi gas with zero-range interactions   The unitary equal-mass Fermi gas with zero-range interactions constitutes a
paradigmatic model system that is relevant to atomic, condensed matter,
nuclear, particle, and astro physics. This work determines the fourth-order
virial coefficient $b_4$ of such a strongly-interacting Fermi gas using a
customized \textit{ab initio} path integral Monte Carlo (PIMC) algorithm. In
contrast to earlier theoretical results, which disagreed on the sign and
magnitude of $b_4$, our $b_4$ agrees within error bars with the experimentally
determined value, thereby resolving an ongoing literature debate. Utilizing a
trap regulator, our PIMC approach determines the fourth-order virial
coefficient by directly sampling the partition function. An on-the-fly
anti-symmetrization avoids the Thomas collapse and, combined with the use of
the exact two-body zero-range propagator, establishes an efficient general
means to treat small Fermi systems with zero-range interactions.

26
The categories of this paper are: bayes-an
35
The categories of this paper are: mtrl-th
16
The categories of this paper are: stat
19
The categories of this paper are: eess
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
0
The categories of this paper are: hep-ph
36
The categories of this paper are: cmp-lg
24
The categories of this paper are: dg-ga