Effects of biases in domain wall network evolution

Abstract

We study the evolution of various types of biased domain wall networks in the early universe. We carry out larger numerical simulations than currently available in the literature and provide a more detailed study of the decay of these networks, in particular by explicitly measuring velocities in the simulations. We also use the larger dynamic range of our simulations to test previously suggested decay laws for these networks, including an ad-hoc phenomenological fit to earlier simulations and a decay law obtained by Hindmarsh through analytic arguments. We find the latter to be in good agreement with simulations in the case of a biased potential, but not in the case of biased initial conditions.

General purpose graphics-processing-unit implementation of cosmological domain wall network evolution

“…The scaling exponents are calculated using a linear fit and ignoring the early part of the simulations (whose dynamics is still dominated by the initial conditions). The calculated exponents are listed in Table I, and are in agreement with previous simulations of boxes of these sizes with CPU versions of the code [27,28]. The listed uncertainties are statistical, from the average of each set of five runs (this is the relevant comparison here); additional systematic uncertainties in these diagnostics are discussed in [8].…”

“…where µ = −1 and ν = 0. For simulations with a smaller dynamic range this asymptotic regime may not be reached, which can be identified by a dependence of the exponents µ and ν on the box size [27,28]. The purpose of this paper is to present a parallel implementation of the PRS algorithm for 2D and 3D domain walls which runs on GPGPUs, using the behaviour of these two quantities to validate the implementation.…”

Stability of domain walls in models with asymmetric potentials

“…We identified relative importance of these factors on fate and decay time of the networks. Effects of part of these factors were studied in the past [3][4][5], however broad analysis was performed for a first time. Moreover, the shaped of the potential around minimum was mentioned as a factor that can influence the stability of the network [3], but this hypothesise was not verified till now.…”

“…• infinite domain walls stretching through the whole Universe, depending on the initial contributions of the vacua [1][2][3][4][5]. During further evolution domains are stretched by the expansion of the Universe, thus both the surface and the curvature radius of domain walls grow.…”

Simulating the symmetron: Domain walls and symmetry-restoring impurities

“…There are many studies in the field theory literature of the dynamics of domain wall networks in the simplest sense (see e.g., the above references as well as [6][7][8][9][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] for recent studies), but very few (if any) when the domain walls could interact with objects, and so it is interesting to understand what effect the presence of "objects" could have on the scaling dynamics of the wall network. There are studies of two-component Bose-Einstein condensates in the literature, e.g., [28,29], in which an interaction between domain walls and vortices is studied.…”