2002/11/09 by Christophe Ringeval, Ringeval, Christophe
Computer Science · Physics and Astronomy · #Astrophysics (astro-ph) #Black Holes and Theoretical Physics #Computational Physics and Python Applications #Cosmology and Gravitation Theories #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #High Energy Physics - Phenomenology (hep-ph) #High Energy Physics - Theory (hep-th) #astro-ph #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.48550/arxiv.hep-ph/0211126
PhD thesis, University of Paris 6 (french), 316 pages, 108 figures. A high resolution postscript version can be found at http://theory.physics.unige.ch/~ringeval/upload/thesemain.ps.gz
arxiv created 2002/11/09 · openalex publication_date 2002/11/09 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
This PhD thesis discusses the internal structure of topological defects, and branes in extra-dimensions, carrying fermionic currents. The general framework in which these objects may appear is presented in the first part while the second part is devoted to the dynamic of cosmic strings, a class of topological defects of uttermost importance to modern cosmology, as it can be obtained from a macroscopic covariant formalism. This formalism offers a unified description of cosmic strings, including the case for which they carry internal currents, and allows the study of their cosmological evolution, and implications, by means of numerical simulations. Its validity has already been confirmed for cosmic string carrying bosonic currents, and the third part provides new results concerning the fermionic currents case. First, the fermion mass spectrum in a cosmic string is computed, and suggests that fermionic currents are usually built on massive propagation modes leading to a new equation of state. This highlights that the usual one parameter macroscopic formalism is not always sufficient in case of fermionic currents. Moreover, contrary to the bosonic case, the dynamics stemming from this equation of state exhibits transitions between the subsonic and supersonic regimes whose consequences in cosmology could be important. The last part is an extension of these results to brane cosmology for which our universe is viewed as a four dimensional domain wall embedded in a five dimensional space-time. In the framework of the Randall-Sundrum model, the masses of the trapped fermions on the brane can be predicted.