In a natural way, every Lie group $G$ is contained in its holomorph Hol($G$) = $G \rtimes $ Aut($G$)
Is Hol$(G)$ always a Lie group?
If the answer is yes our main questions:
1.For a left invariant metric $g$ of Hol($G$), are there always two left invariant metrics $g_{1}$ and $g_{2}$ of $G$ and Aut($G$), respectively such that $g$ is conformal to the product of $g_{1}$ and $g_{2}$? (motivated by $G=\mathbb{R}$, as an example of this situation)
- For what type of Lie groups, $G$ is a totally geodesic submanifold of its holomorph?
And finally: can one write the lie algebra of Hol($G$) in term of Lie algebras of $G$ and $Aut(G)$ and also the natural action of $Aut(G)$ on the Lie algebra of $G$?