High-Speed Cylindrical Collapse of Perfect Fluid

The gravitational collapse of cylindrically distributed perfect fluid isstudied. We assume the collapsing speed of fluid is very large and investigatesuch a situation by recently proposed high-speed approximation scheme. We showthat if the value of the pressure divided by the energy density is boundedbelow by some positive value, the high-speed collapse is necessarily halted.This suggests that the collapsing perfect fluid of realistic ideal gasexperiences the pressure bounce. However even in the case of mono-atomic idealgas, arbitrarily large tidal force for freely falling observers are realizableby setting the initial collapsing velocity exceedingly large. In order that thehigh-speed collapse of cylindrical perfect fluid forms spacetime singularity,the equation of state should be very soft.Comment: 15pages, 1figure, PTPTe