相关论文: Sweeping Away the Monopole Problem
Long periods of coherent oscillations of moduli fields relax the bound on possible initial monopole density in the early universe, and in some cases eliminate it completely.
The possibility of the existence of magnetic charges is one of the greatest unsolved issues of the physics of this century. The concept of magnetic monopoles has at least two attractive features: (i) Electric and magnetic fields can be…
These lectures review certain topological defects and aspects of their cosmology. Unconventional material includes brief descriptions of electroweak defects, the structure of domain walls in non-Abelian theories, and the spectrum of…
We use the moduli space approximation to study the time evolution of magnetically charged configurations in a theory with an SU(N+2) gauge symmetry spontaneously broken to U(1) x SU(N) x U(1). We focus on configurations containing two…
We investigate the high temperature behavior of SU(5) in its minimal version. We show that there exists a range of parameters of the Higgs potential for which the symmetry remains broken at high temperature, thus avoiding the phase…
The electromagnetic decay and final annihilation of magnetic monopole-antimonopole pairs formed in the early universe has been proposed as a possible mechanism to produce the highest energy cosmic rays. We show that for a monopole abundance…
We study a gauge theory model where there is an intermediate symmetry breaking to a meta- stable vacuum that breaks a simple gauge group to a U (1) factor. Such models admit the existence of meta-stable magnetic monopoles, which we dub…
We construct multimonopole solutions containing N-1 distinct fundamental monopoles in SU(N) gauge theory. When the gauge symmetry is spontaneously broken to U(1)^{N-1}, the monopoles are all massive, and we show that the fields can be…
We study topological defects arising in the Grand Unification Model $SU(6)_L\otimes SU(6)_c \otimes SU(6)_R \times Z_3$. We show that the model does not contain domain walls, while it produces massive magnetic monopoles and it may,…
Topologically protected sheet-like surfaces, called domain walls, form when the potential of a field has a discrete symmetry that is spontaneously broken. Since this condition is commonplace in field theory, it is plausible that many of…
We investigate cosmological consequences of an extended gravity model which belongs to the same class studied by Accetta and Steinhardt in an extended inflationary scenario. But we do not worry about inflation in our model; instead, we…
It is well known that the spontaneous breaking of discrete symmetries may lead to conflict with big-bang cosmology. This is due to formation of domain walls which give unacceptable contribution to the energy density of the universe. On the…
Recently, an interesting class of the direct gauge mediation supersymmetry (SUSY) breaking models are proposed, in which the minimum of the potential of the SUSY breaking field is determined by the inverted hierarchy mechanism. We consider…
In order to obtain the geometry of a global monopole without cosmological constant and electric charge in $2+1-$ dimensions we make use of the broken $% O(2)$ symmetry. In the absence of exact solution we determine the series solutions for…
Large charge density, unlike high temperature, may lead to nonrestoration of global and gauge symmetries. Supersymmetric GUTs with the appealing scenario of unification scale being generated dynamically naturally contain global continuous…
Motivated by Grand Unification, we study the properties of domain walls formed in a model with $SU(5)\times Z_2$ symmetry which is spontaneously broken to $SU(3) \times SU(2) \times U(1)/Z_6$, and subsequently to $SU(3) \times U(1)/Z_3$.…
We reexamine a recently proposed non-inflationary solution to the monopole problem, based on the possibility that spontaneously broken Grand-Unified symmetries do not get restored at high temperature. We go beyond leading order by studying…
Magnetic monopole solutions naturally arise in the context of spontaneously broken gauge theories. When the unbroken symmetry includes a non-Abelian subgroup, investigation of the low-energy monopole dynamics by means of the moduli space…
We study the cosmology of the Supersymmetric Standard Model augmented by a gauge singlet to solve the $\mu$-problem and describe the evolution of the domain walls which are created during electroweak symmetry breaking due to the discrete…
We find the spectrum of magnetic monopoles produced in the symmetry breaking SU(5) to [SU(3)\times SU(2)\times U(1)']/Z_6 by constructing classical bound states of the fundamental monopoles. The spectrum of monopoles is found to correspond…