Cylinders as Left Invariant CMC Surfaces in $\operatorname{Sol}_3$ and $E(κ,τ)$-Spaces Diffeomorphic to $\mathbb{R}^3$
In the present paper we give a geometric proof for the existence of cylinders with constant mean curvature $H>H(X)$ in certain simply connected homogeneous three-manifolds $X$ diffeomorphic to $\mathbb{R}^3$, which always admit a Lie group structure. Here, $H(X)$ denotes the critical value for which constant mean curvature spheres in $X$ exist. Our cylinders are generated by a simple closed curve under a one-parameter group of isometries, induced by left translations along certain geodesics. In the spaces $\operatorname{Sol}_3$ and $\widetilde{\operatorname{PSL}}_2(\mathbb{R})$ we establish existence of new properly embedded constant mean curvature annuli. We include computed examples of cylinders in $\operatorname{Sol}_3$ generated by non-embedded simple closed curves.