The correct relation between γ = C _ P C _ V and temperature T is :

The ratio of molar specific heat capacity at constant pressure to the molar specific heat capacity at constant volume is

$\dfrac{{C}_{P}}{{C}_{V}} = \gamma$

where $\gamma$ is constant for a given gas.

Therefore,

$\dfrac{{C}_{P}}{{C}_{V}} ∝ {T}^{0}$