Stability of sigma-model strings and textures

  title={Stability of sigma-model strings and textures},
  author={Richard S. Ward},
  journal={Classical and Quantum Gravity},
  • R. S. Ward
  • Published 14 January 2002
  • Mathematics, Physics
  • Classical and Quantum Gravity
In flat spacetime, sigma-model strings and textures are both unstable: they tend to collapse (and subsequently decay). With sufficient cosmological expansion, however, they are stable in a generalized sense: a small perturbation will cause them to change their shape, but they do not decay. The current rate of expansion is sufficient to stabilize strings, but not textures. 
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External Stability for Spherically Symmetric Solutions in Lorentz Breaking Massive Gravity
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We investigate classically (iso)spinning topological soliton solutions in (2+1)- and (3+1)-dimensional models; more explicitly isospinning lump solutions in (2+1) dimensions, Skyrme solitons in (2+1)


Texture: A cosmological topological defect.
  • Davis
  • Physics
    Physical review. D, Particles and fields
  • 1987
The notions of phase transition and causality, combined with the standard cosmological model, lead to the appearance of topological defects in the early Universe, and the whole Universe takes on a winding number.
Semilocal cosmic strings.
It is shown that the presence of global symmetries in a Lagrangian can lead to U(1) flux-tube solutions even when the vacuum manifold is simply connected, and it is explicitly proved that semilocal magnetic monopoles cannot exist.
Pair production in the collapse of a Hopf texture
We consider the collapse of a global `Hopf' texture and examine the conjecture, disputed in the literature, that monopole-antimonopole pairs can be formed in the process. We show that such
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Collapse of exotic textures
The ordering of scalar fields after a phase transition in which a group G of global symmetries is spontaneously broken to a subgroup H provides a possible explanation for the origin of structure in
Bogomol'nyi bounds for cosmic strings
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We study the shrinking of solitons in the original (2 + 1)-dimensional sigma model. We show that the rate of this shrinking for a single soliton can be estimated analytically. We perform numerical
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The Skyrme-Faddeev system, a modified O(3) sigma model in three space dimensions, admits topological solitons with nonzero Hopf number. One may learn something about these solitons by considering the
Global texture as the origin of cosmic structure.
  • Turok
  • Physics
    Physical review letters
  • 1989
Texture is shown to have significant advantages over the "standard" inflationary fluctuations in having more power on large scales, and producing nonlinear structures at high redshift.
Global texture and the microwave background.
The metric perturbation produced by a collapsing knot'' of global texture in a flat background is calculated, leading to a prediction for the microwave anisotropy pattern produced in the global-texture scenario for large-scale structure formation.