The vacuum energy density now is small or zero but must have been prodigious if the universe was once hotter than $T_c\sim {10}^{15}$ K and if elementary-particle symmetry is spontaneously broken by a Higgs mechanism. If symmetry is broken nondynamically, in the hot disordered phase the huge vacuum energy density is nevertheless negligible, compared to the energy density of ultrarelativistic particles. Because the broken symmetry is non-Abelian, the long-range forces arising on symmetry restoration need not lead back to an anisotropic, inhomogeneous, or domain-structure universe.

• Received 12 October 1976

DOI:https://doi.org/10.1103/PhysRevLett.38.255