Instability of static semiclosed worlds in generalized Galileon theories

We consider generalized Galileon theories within general relativity in four-dimensional spacetime. We provide the argument showing that the generalized Galileons described by a wide class of Lagrangians do not admit stable, static, spherically symmetric semiclosed worlds. We also show that in a class of theories with p⊥=−ρ (where p⊥ is transverse pressure and ρ is energy density), semiclosed worlds, if they exist, would be observed as objects of negative mass.