when they exploit the relationship by Berry and Keating between the Riemann zeros and eigenvalues of random matrices
why do they choose $$ \frac{\gamma _{n}}{2\pi}log \frac{\gamma}{2\pi e} $$ as a Random variable
however why are they ignoring the number $ \frac{1}{\pi}arg \zeta (1/2+is) $
i am referring to the paper
http://www.maths.bris.ac.uk/~majpk/papers/67.pdf
why he just ignore the scillating term proportional to the argument of the zeta function of the critical lines.