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This book sheds new light on topological defects in widely differing systems, using the Velocity-Dependent One-Scale Model to better understand their evolution. Topological defects - cosmic strings, monopoles, domain walls or others - necessarily form at cosmological (and condensed matter) phase transitions. If they are stable and long-lived they will be fossil relics of higher-energy physics. Understanding their behaviour and consequences is a key part of any serious attempt to understand the universe, and this requires modelling their evolution. The velocity-dependent one-scale model is the only fully quantitative model of defect network evolution, and the canonical model in the field. This book provides a review of the model, explaining its physical content and describing its broad range of applicability.

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Introduction to Defects.- Cosmic Strings.- Domain Walls.- The Rest of the Zoo.- Model Extensions.- Defects in condensed matter.

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Carlos Martins is an FCT Research Professor at the Center for Astrophysics of U. Porto (CAUP), and the Head of its Training Unit. He has an undergraduate degree in Astronomy from U. Porto, and a PhD in Theoretical Physics from U. Cambridge. He works on fundamental cosmology and particle astrophysics, focusing on precision consistency tests of standard cosmology and astrophysical searches for new physics.

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