Related papers: Evolution of String-Wall Networks and Axionic Doma…
We study the evolution of biased domain walls in the early universe. We explicitly discuss the roles played by the surface tension and volume pressure in the evolution of the walls, and quantify their effects by looking at the collapse of…
We study the evolution of domain wall networks and their phenomenological implications in a model of a real scalar $\chi$, where a $Z_2$-symmetry is slightly broken by a potential bias $V_{bias}$. It is demonstrated that the latter triggers…
We show that all kinds of biasing of cosmological phase transitions produce qualitatively new type of domain wall networks. The biased networks consist of compact, finite size, bag-like wall structures and exhibit a generic instability. The…
We simultaneously study gravitational waves (GWs) and free axions emitted from axionic string-wall networks in the early universe using advanced 3D lattice simulations. Our simulations start before the Peccei-Quinn phase transition and end…
We examine the collapse of an axion domain wall bounded by an axionic string. It is found that the collapse proceeds quickly and axion domain walls disappear. However axions are emitted in the collapse and its energy density increases…
Domain wall networks in the early universe, formed upon spontaneous breaking of a discrete symmetry, have a rich impact on cosmology. Yet, they remain somewhat unexplored. We introduce a new analytic strategy to understand better the domain…
We point out that domain wall formation is a more common phenomenon in the Axiverse than previously thought. Level crossing could take place if there is a mixing between axions, and if some of the axions acquire a non-zero mass through…
We study domain walls which can be created in the Standard Model under the assumption that it is valid up to very high energy scales. We focus on domain walls interpolating between the physical electroweak vacuum and the global minimum…
We study a number of domain wall forming models where various types of defect junctions can exist. These illustrate some of the mechanisms that will determine the evolution of defect networks with junctions. Understanding these mechanisms…
Axions have for some time been considered a plausible candidate for dark matter. They can be produced through misalignment, but it has been argued that when inflation occurs before a Peccei-Quinn transition, appreciable production can…
We study topological defects in multi-axion models arising from multiple Peccei-Quinn (PQ) scalars. Using a simplified two-axion system, we reveal fundamental differences in the evolution of these defects compared to single-axion scenarios.…
In this study, we examine the domain wall within the framework of a cosmological harmonic oscillator. We investigate the interaction between the domain wall and a periodic background field, which can induce perturbations in the oscillatory…
The domain wall problem of the Peccei-Quinn mechanism can be solved if the Peccei-Quinn symmetry is explicitly broken by a small amount. Domain walls decay into axions, which may account for dark matter of the universe. This scheme is…
A recent study has shown that domain walls with inflationary initial fluctuations exhibit remarkable stability against population bias due to long-range correlations, challenging the claims of prior research. In this paper, we study the…
Employing the publicly available CosmoLattice code, we conduct numerical simulations of a domain wall network and the resulting gravitational waves (GWs) in a radiation-dominated Universe in the $Z_2$-symmetric scalar field model. In…
Cold dark matter axions produced in the post-inflationary Peccei-Quinn symmetry breaking scenario serve as clear targets for their experimental detection, since it is in principle possible to give a sharp prediction for their mass once we…
The axion causes two serious cosmological problems, domain wall and isocurvature perturbation problems. Linde pointed that the isocurvature perturbations are suppressed when the Peccei-Quinn (PQ) scalar field takes a large value $\sim…
The damping of the axionic string motion due to the surrounding plasma is estimated by a detailed calculation of the fermion scatter from a global string and it is shown that the friction force on the string can be neglected before the…
We consider the decay of a metastable domain wall. The transition proceeds through quantum tunneling, and we calculate in arbitrary number of dimensions the preexponential factor multiplying the leading semiclassical exponential expression…
We study the production of gravitational waves from cosmic domain walls created during phase transition in the early universe. We investigate the process of formation and evolution of domain walls by running three dimensional lattice…