NAMBU-GOTO MEMBRANE WITH REPULSIVE GRAVITY

We describe an example of thin charged shell with equation of state ϵ = τ (Nambu- Goto membrane; τ is tension) that allows a stable configuration such as it exist a region around the shell where gravity has a repulsive behavior. The shell corresponds to a naked Reissner-Nordstrom solution having a charge Q > M, and positive mass M.