A note on blowup of smooth solutions for relativistic Euler equations with infinite initial energy

We study the singularity formation of smooth solutions of the relativistic Euler equations in (3+1)-dimensional spacetime for infinite initial energy. We prove that the smooth solution blows up in finite time provided that the radial component of the initial generalized momentum is sufficiently large without the conditions (M(0)>0) and (s^{2}, which were two key constraints stated in Pan and Smoller (Commun Math Phys 262:729–755, 2006).