A branch of excitations for a three-dimensional system has a dispersion relation ϵ(k) = Ak2/3, where A is constant and k is magnitude of wave vector. The excitations are bosonic in nature and chemical potential (μ) is zero. The heat capacity at constant volume (CV) of the system varies on absolute temperature (T) as \(c_v \propto T^{α}\). The value of α upto two decimal place is