Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The "non-regularizability" of gapless free fermion Hamiltonian protected
  by on-site symmetries   The non-regularizability of free fermion field theories, which is the root of
various quantum anomalies, plays a central role in particle physics and modern
condensed matter physics. In this paper, we generalize the Nielsen-Ninomiya
theorem to all minimal nodal free fermion field theories protected by the time
reversal, charge conservation, and charge conjugation symmetries. We prove that
these massless field theories cannot be regularized on a lattice.

18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
20
The categories of this paper are: acc-phys
6
The categories of this paper are: astro-ph
25
The categories of this paper are: patt-sol
8
The categories of this paper are: hep-ex