Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nucleon gravitational form factors from instantons: forces between quark
  and gluon subsystems   Using the instanton picture of the QCD vacuum we compute the nucleon $\bar
c^Q(t)$ form factor of the quark part of the energy momentum tensor (EMT). This
form factor describes the non-conservation of the quark part of EMT and
contributes to the quark pressure distribution inside the nucleon. Also it can
be interpreted in terms of forces between quark and gluon subsystems inside the
nucleon.
  We show that this form factor is parametrically small in the instanton
packing fraction. Numerically we obtain for the nucleon EMT a small value of
  $\bar c^Q(0)\simeq 1.4\cdot 10^{-2}$ at the low normalisation point of $\sim
0.4$ GeV$^2$. This smallness implies interesting physics picture - the forces
between quark and gluon mechanical subsystems are smaller than the forces
inside each subsystem. The forces from side of gluon subsystem squeeze the
quark subsystem - they are compression forces. Additionally, the smallness of
$\bar c^Q(t)$ might justify Teryaev's equipartition conjecture. We estimate
that the contribution of $\bar c^Q (t)$ to the pressure distribution inside the
nucleon is in the range of 1 -20 % relative to the contribution of the quark
$D$-term.

5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
35
The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
16
The categories of this paper are: stat
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga