  We explore the upper bound of the Lyapunov exponent for test particles that
maintain equilibrium in the radial direction near the charged black brane with
the hyperscaling violating factor. The influences of black brane parameters
(hyperscaling violation exponent $\theta$ and dynamical exponent $z$) are
investigated. We show that the equilibrium in the radial direction of test
particles can violate the chaos bound. The chaos bound is more easily violated
for the near-extremal charged black branes. When the null energy condition
($T_{\mu\nu}\xi^\mu\xi^\nu \geq 0$) is broken, the bound is also more likely to
be violated. These results indicate that the chaos bound of particle motion is
related to the temperature of the black hole and the null energy condition
(NEC). By considering the zero-temperature and $T_{\mu\nu}\xi^\mu\xi^\nu=0$
cases, we obtain the critical parameters $\theta_c$ and $z_c$ for the violation
of chaos bound. The chaos bound is always satisfied in the range $\theta >
\theta_c$ or $z>z_c$.

High Energy Physics - Theory