$k(P_{yx}) = {\mathrm{const}}\gamma$. ](kfig){width="1\columnwidth"}

                                                                         LD(ex)               LD(sh)                   MD
  -------------------------------------------------------- -------------------- -------------------- --------------------
  Mean, $\kappa_1(\alpha)$                                   $-1.515 \pm 0.004$   $-1.518 \pm 0.004$   $-1.521 \pm 0.004$
  Variance, $\kappa_2(\alpha)$                               $ 0.185 \pm 0.003$   $ 0.185 \pm 0.003$   $ 0.184 \pm 0.003$
  Skewness, $\kappa_3(\alpha)/\kappa_2(\alpha)^{3/2}$        $ -0.11 \pm  0.03$   $ -0.16 \pm  0.03$   $ -0.14 \pm  0.03$
  Excess kurtosis, $\kappa_4(\alpha)/\kappa_2(\alpha)^2$     $  0.15 \pm  0.09$   $  0.19 \pm  0.07$   $  0.08 \pm  0.07$

In this section we continue to study the same Molecular Dynamics (MD) model of a shear flow in a simple fluid, as we did in [Ref. [@PRE2016III]]{}. Here we briefly summarize, that we consider $N$ particles of equal mass $m$, interacting through the Weeks-Chandler-Anderson (WCA) potential [@WCA] in three dimensions. A constant shear rate $\gamma$, which is the nonequilibrium force driving a current of linear momentum, is applied by the SLLOD equations of motion with Lees-Edwards boundary conditions [@EvansMorriss Chapter 6]. A constant temperature was maintained by the Nosé-Hoover (NH) thermostat [@FrenkelSmit Chapter 6].

The current in our MD system is given by the $yx$-pressure tensor component, $P_{yx}$, which expresses a flow of $x$ momentum in the $y$-direction [@EvansMorriss Sec. 3.8]: $$P_{yx} = V^{-1} \sum_{i=1}^{N} (p_{yi} p_{xi} /m + y_i F_{xi}),$$ where $V$ is the 