Discontinuity problem in the linear stability analysis of thin-shell wormholes

We investigate the infinite discontinuity points of the stability diagram in thin-shell wormholes. The square of the speed of sound beta(2)(0), which is expressed in terms of pressure and energy density at equilibrium on the throat, arises with a divergent amplitude. As this is physically non-acceptable, we revise the equation of state, such that by fine-tuning of the pressure at static equilibrium, which is at our disposal, we eliminate such singularity. The efficacy of the method is shown in Schwarzschild, extremal Reissner-Nordstrom and dilaton thin-shell wormholes.