Cosmological Implication of Electroweak Monopole

Y.M Cho,Y Aharonov,L Bravina,S Kabana

doi:10.1051/epjconf/201818202030

Abstract

We estimate the remnant electroweak monopole density of the standard model in the present universe. We show that, although the electroweak phase transition is of the first order, the monopole production comes from the thermal fluctuations of the Higgs field after the phase transition, not the vacuum bubble collisions during the phase transition. Moreover, most of the monopoles produced initially are annihilated as soon as created, and this annihilation continues very long time, longer than the muon pair annihilation time. As the result the remnant monopole density at present universe becomes very small, of 10-11 of the critical density, too small to be the dark matter. We discuss the physical implications of our results on the ongoing monopole detection experiments.

Highlights

Ever since Dirac has proposed the Dirac monopole generalizing the Maxwell’s theory, the monopole has become an obsession in physics [1]
The ’tHooftPolyakov monopole exists only in an hypothetical theory, and the grand unification monopole which could have been amply produced at the grand unification scale in the early universe probably has become completely irrelevant at present universe after the inflation
Since the decoupling temperature of the electroweak monopole is around 0.5 MeV, the free streaming monopoles startas non-relativistic. Eventually they are accelerated by the intergalactic magnetic field, and they become extremely relativistic. In this talk we have studied the cosmic production and the successive evolution of the electroweak monopole, and estimated the remnant monopole density in the present universe

Summary

Introduction

Ever since Dirac has proposed the Dirac monopole generalizing the Maxwell’s theory, the monopole has become an obsession in physics [1]. The purpose of this letter is to discuss the cosmological production and successive evolution of the electroweak monopole to predict the remnant monopole density of the standard model at present universe. This tells that the standard model has a different type of monopole topology, the combination of the nonAbelian S U(2) monopole topology and the Abelian U(1)Y monopole topology [5, 22] This makes the electroweak monopole a hybrid between Dirac and ’tHooft-Polyakov. Another way to see the existence of the monopole topology is that the standard model (after the symmetry breaking) contains the electromagnetic part which is essentially Maxwell’s theory, except the U(1)em becomes non-trivial. In the following the estimate of mass of the electroweak monopole plays a crucial role for us to estimate the remnant monopole density

Electroweak Phase Transition

Cosmological Production of Electroweak Monopole

Cosmic Evolution of Electroweak Monopole

BT 2r2

Discussion