Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Marshall sign and the doped $t-J$ model   Marshall sign as a sole source of sign problem hidden in an antiferromagnet
is explored under doping. By tracking the Marshall sign, a zero spectral weight
$Z$ is revealed in the doped antiferromagnetic system. $Z=0$ is caused by a
phase string induced by the ``bare'' hole. By eliminating such a phase string
through nonlocal transformations, a non-perturbative scheme is obtained. It is
argued that this formalism provides a unique way to get access to the real
ground state of the doped $t-J$ model for both one- and two-dimensions.

20
The categories of this paper are: acc-phys
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
37
The categories of this paper are: supr-con
13
The categories of this paper are: quant-ph
17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
8
The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
2
The categories of this paper are: math
16
The categories of this paper are: stat