Rutwig Campoamor-Stursberg Intrinsic formulae for the Casimir operators of semidirect products of the exceptional Lie algebra $G_{2}$ and a Heisenberg Lie algebra (264K, pdf) ABSTRACT. We show that the Casimir operators of the semidirect products $G_{2}\overrightarrow{\oplus}_{2\Gamma_{\left( a,b\right) }\oplus\Gamma_{\left( 0,0\right) }}\frak{h}$ of the exceptional Lie algebra $G_{2}$ and a Heisenberg algebra $\frak{h}$ can be constructed explicitly from the Casimir operators of $G_{2}$.