Allen E. Everett

Left-right symmetric theories and vacuum domain walls and strings

Abstract Theories in which a discrete left-right symmetry is spontaneously broken are expected to lead to the formation of vacuum domain walls. Although the existence of such walls at the present epoch is observationally excluded, we show that such theories are allowed if the discrete symmetry is embedded in a larger continuous symmetry, e.g., SO(10), spontaneously broken at higher temperatures. In this case vacuum strings are formed when the larger symmetry is broken, and these become connected by domain walls when the discrete symmetry is broken. The bounded domain walls tend to shrink, and the system of strings and domain walls decays before its energy density becomes comparable to that of matter. In particular, our arguments allow the symmetry breaking pattern SO(10) → … S[O(6)×O(4)] → SU(3)×SU(2)×U(1) which has been proposed by others.

Can a Circulating Light Beam Produce a Time Machine

In a recent paper, Mallett found a solution of the Einstein equations in which closed timelike curves (CTC’s) are present in the empty space outside an infinitely long cylinder of light moving in circular paths around an axis. Here we show that, for physically realistic energy densities, the CTC’s occur at distances from the axis greater than the radius of the visible universe by an immense factor. We then show that Mallett’s solution has a curvature singularity on the axis, even in the case where the intensity of the light vanishes. Thus it is not the solution one would get by starting with Minkowski space and establishing a cylinder of light.

Comment on “the behavior of maxwell's equations under real superluminal lorentz transformations”

Abstract Negi et al. have recently obtained field equations for the superluminal electromagnetic field, in theories based on real superluminal transformations along a “tachyon corridor”. Their results differ from equations obtained some time ago by the present authors. We trace the source of the discrepancy to the failure of Negi et al. to consistently transform all relevant quantities from the old to the new Lorentz frame.

PION-HYPERON RESONANCES AND POSSIBLE NONCONSERVATION OF ISOTOPIC SPIN

A possibile explanation of the pion-hyperon resonances is suggested in terms of global symmetry and the possibility that there may be some violation of isotopic spin con servation in strong interactions. In this connection, an alternative spin assigmment of P/sub 3/2 is proposed for the 1520Mev pion-hyperon resonance. Some possibile experimental tests of these ideas are suggested. (auth)