相关论文: Testing cosmological defect formation in the labor…
Some aspects of the theory of cosmological perturbations from cosmic strings and other topological defects are outlined, with particular reference to a simple example: a spatially flat CDM-dominated universe. The conserved energy-momentum…
We investigate the cosmological consequences of particle physics theories that admit stable loops of superconducting cosmic string - {\it vortons}. General symmetry breaking schemes are considered, in which strings are formed at one energy…
A (very) brief review of topological defects and their possible cosmic roles. I emphasize in particular that superheavy defects needed for structure formation can peacefully coexist with inflation, despite the claims to the contrary which…
The topology of space is usually assumed simply connected, but could be multi-connected. We review in the latter case the possibility that topological defects arising at high energy phase transitions might still be present and find that…
${\rm B - L}$ cosmic strings form in a wide class of theories beyond the Standard Model which contain a ${\rm U}(1)_{{\rm B - L}}$ gauge symmetry. They can form at the end of hybrid inflation and explain, together with inflation, the Cosmic…
We carry out numerical simulations to investigate spontaneous vortex formation during a temperature quench of a superconductor film from the normal to the superconducting phase in the absence of an external magnetic field. Our results agree…
As a hypothetical topological defect in the geometry of spacetime, vortex strings play a crucial role in shaping the clusters of galaxies that exist today, and their distinct features can provide observable clues about the early universe's…
Defects in superfluid 3He, high-Tc superconductors, QCD colour superfluids and cosmic vortons can possess (anti)ferromagnetic cores, and their generalisations. In each case there is a second order parameter whose value is zero in the bulk…
The formation of vortex loops (global cosmic strings) in an O(2) linear sigma model in three spatial dimensions is analyzed numerically. For over-damped Langevin dynamics we find that defect production is suppressed by an interaction…
In these lectures, I review the current status of cosmic strings and cosmic superstrings. I first discuss topological defects in the context of Grand Unified Theories, focusing in particular in cosmic strings arising as gauge theory…
Cosmic strings are linear concentrations of energy that may be formed at phase transitions in the very early universe. At one time they were thought to provide a possible origin for the density inhomogeneities from which galaxies eventually…
Cosmic strings are linear concentrations of energy that form whenever phase transitions in the early universe break axial symmetries as originally shown by Kibble. They are the result of frustrated order in the quantum fields responsible…
Linear defects are generic in continuous media. In quantum systems they appear as topological line defects which are associated with a circulating persistent current. In relativistic quantum vacuum they are known as cosmic strings, in…
In the framework of the Closed-Time-Path formalism, we show how topological defects may arise in Quantum Field Theory as result of a localized (inhomogeneous) condensation of particles. We demonstrate our approach on two examples; kinks in…
We study the behaviour and consequences of cosmic string networks in contracting universes. They approximately behave during the collapse phase as a radiation fluids. Scaling solutions describing this are derived and tested against…
Cosmic strings are predicted by many field-theory models, and may have been formed at a symmetry-breaking transition early in the history of the universe, such as that associated with grand unification. They could have important…
The formation of topological defects in a second order phase transition in the early universe is an out-of-equilibrium process. Condensed matter experiments seem to support Zurek's mechanism, in which the freezing of thermal fluctuations…
Topological defects can have significant cosmological consequences, so their production must be examined carefully. It is usually assumed that topological defects are produced if the temperature becomes sufficiently high, but in reality…
Making use of the wealth of new observational data coming from the sky it is possible to constrain particle physics theories beyond the Standard Model. One way to do this is illustrated in this article: a subset of theories admits cosmic…
In supersymmetric theories, topological defects can have nontrivial behaviors determined purely by whether or not supersymmetry is restored in the defect core. A well-known example of this is that some supersymmetric cosmic strings are…