domain wall

In general, a *domain wall* is a defect of codimension 1.

More specifically, in a gauge theory with a degenerate vacuum (such as when a Higgs mechanism applies), the moduli space of vacua is the quotient $G/H$ (the coset) of the gauge group $G$ by the stabilizer subgroup $H \hookrightarrow G$ of any of these vacua (spontaneous symmetry breaking).

This means that gauge equivalence classes of vacuum configurations on a spacetime $X$ are given by homotopy classes of maps $X \to \Pi(G/H)$ (where the notation on the right denotes the underlying homotopy type of the coset space, $\Pi$ is the shape modality).

If spacetime is locally to be taken of the form $\mathbb{R} \times (\mathbb{R}^3 - D^1 \times \mathbb{R}^2)$, hence with a 1-dimensional (“wall”-like) piece taken out, them homotopy classes of maps $X \to \Pi(G/H)$ are classified by the 0-th homotopy group $\pi_0(G/H)$. For a given nontrivial element here the corresponding vacuum is said to contain a **domain wall defect**.

For more see at *QFT with defects* the section *Topological defects from spontaneously broken symmetry*.

singularity | field theory with singularities |
---|---|

boundary condition/brane | boundary field theory |

domain wall/bi-brane | QFT with defects |

- Alexander Vilenkin, E.P.S. Shellard,
*Cosmic strings and other topological defects*, Cambridge University Press (1994)

See also:

- Wikipedia,
*Domain wall*

Last revised on November 12, 2020 at 10:58:37. See the history of this page for a list of all contributions to it.