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Related papers: Cosmic string Y-junctions: a comparison between fi…

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We consider strings with the Nambu action as extremal surfaces in a given space-time, thus, we ignore their back reaction. Especially, we look for strings sharing one symmetry with the underlying space-time. If this is a non-null symmetry,…

General Relativity and Quantum Cosmology · Physics 2007-05-23 H. -J. Schmidt , U. Semmelmann

We discuss formation of cosmic strings associated with a spontaneously broken approximate $U(1)$ symmetry by performing classical field-theoretical simulations. An original $U(1)$ symmetry is explicitly broken down to its subgroup $Z_N$…

High Energy Physics - Phenomenology · Physics 2024-10-11 Kohei Fujikura , Mairi Sakellariadou , Michiru Uwabo-Niibo , Masahide Yamaguchi

We study, within the Nambu-Goto approximation, the stability of massive string junctions under the influence of the tensions of three strings joining together in a Y-type configuration. The relative angle $\beta$ between the strings at the…

High Energy Physics - Theory · Physics 2015-06-23 A. Avgoustidis , A. Pourtsidou , M. Sakellariadou

The precise calculation of gravitational wave (GW) and particle emissions from cosmic string networks is of significant theoretical and experimental interest. In this Letter, we perform numerical simulations of near-global and local string…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-02 Zizhuo Zhao , Ligong Bian , Jing Shu

We study the self-similar motion of a string in a self-similar spacetime by introducing the concept of a self-similar string, which is defined as the world sheet to which a homothetic vector field is tangent. It is shown that in Nambu-Goto…

General Relativity and Quantum Cosmology · Physics 2016-09-15 Takahisa Igata , Tsuyoshi Houri , Tomohiro Harada

Recent work suggests that fundamental and Dirichlet strings, and their (p,q) bound states, may be observed as cosmic strings. The evolution of cosmic string networks, and therefore their observational signals, depends on what happens when…

High Energy Physics - Theory · Physics 2009-11-10 Mark G. Jackson , Nicholas T. Jones , Joseph Polchinski

We study the dynamics of Nambu-Goto cosmic string loops coupled to a massive Kalb-Ramond field. This coupling provides a framework for describing the interaction between the cosmic string and the gauge field. Within this setup, we compute…

High Energy Physics - Theory · Physics 2025-09-24 I. Yu. Rybak

Cosmic strings may have formed in the early universe due to the Kibble mechanism. While string networks are usually modeled as being of Nambu-Goto type, this description is understood to be a convenient approximation, which neglects the…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-01 A. R. R. Almeida , C. J. A. P. Martins

We study the realistic structure of F-term Nambu-Goto cosmic strings forming in a general supersymmetric Grand Unified Theory implementation, assuming standard hybrid inflation. Examining the symmetry breaking of the unification gauge group…

General Relativity and Quantum Cosmology · Physics 2016-04-26 Erwan Allys

The idea of GUT implies that the universe went through a series of phase transitions during which topological defects are expected to form. We investigate here the genericity of cosmic strings formation in realistic SUSY GUTs models. We…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. Rocher , R. Jeannerot , M. Sakellariadou

We consider aspects of the low energy description of global cosmic strings. In the non-relativistic limit, we study the extent to which these are described by the combination of the Nambu-Gotto and Kalb-Ramond actions. While in a formal…

High Energy Physics - Phenomenology · Physics 2022-09-21 Michael Dine

We perform the numerical field evolution for the collision of two Abelian type I cosmic strings. We present evidence that, for collisions at small but characteristic relative velocities and angles, these cosmic strings do not exchange ends…

High Energy Physics - Phenomenology · Physics 2009-10-30 Luis M. A. Bettencourt , Pablo Laguna , Richard A. Matzner

Cosmic strings provide a radically different paradigm for the formation of structure to the prevailing inflationary one. They afford some extra technical complications: for example, the calculation of the power spectrum of matter and…

Astrophysics · Physics 2007-05-23 Mark Hindmarsh , Mairi Sakellariadou , Graham R. Vincent

The topic of cosmic strings provides a bridge between the physics of the very small and the very large. They are predicted by some unified theories of particle interactions. If they exist, they may help to explain some of the largest-scale…

High Energy Physics - Phenomenology · Physics 2010-11-01 M. B. Hindmarsh , T. W. B. Kibble

We investigate cosmic strings arising from a hierarchical gauge symmetry breaking sequence, $\mathrm{SU}(2) \times \mathrm{U}(1) \rightarrow \mathrm{U}(1) \times \mathrm{U}(1) \rightarrow \mathrm{U}(1)' \rightarrow \text{Nothing}$. This…

High Energy Physics - Phenomenology · Physics 2025-06-19 Akifumi Chitose , Masahiro Ibe , Satoshi Shirai , Yaxuan Wen

Cosmic strings are predicted by many field-theory models, and may have been formed at a symmetry-breaking transition early in the history of the universe, such as that associated with grand unification. They could have important…

High Energy Physics - Theory · Physics 2010-05-07 Edmund J. Copeland , T. W. B. Kibble

We study the collisions of elastic superconducting strings, also referred to as current-carrying strings, formed in a $U_{\rm local}(1) \times U_{\rm global}(1)$ field-theory model, using three-dimensional numerical field-theoretic…

High Energy Physics - Phenomenology · Physics 2024-06-24 Takashi Hiramatsu , Marc Lilley , Daisuke Yamauchi

Chiral cosmic strings are produced naturally at the end of inflation in supersymmetric models where the symmetry is broken via a D-term. Consequently in such theories, where both inflation and cosmic strings contribute to the density and…

Astrophysics · Physics 2009-10-31 A. C. Davis , T. W. B. Kibble , M. Pickles , D. A. Steer

Time evolution of a circular cosmic string loop is investigated by numerically solving the field equations for the scalar and the gauge fields consisting of the vortex. It is shown that the result agrees with an analytic estimate based on…

Astrophysics · Physics 2009-10-22 Michiyasu Nagasawa , Jun'ichi Yokoyama

Cosmic superstring loops generically contain strings of different tensions that meet at Y-junctions. These loops evolve non-periodically in time, and have cusps and kinks that interact with the junctions. We study the effect of junctions on…

High Energy Physics - Theory · Physics 2009-12-30 P. Binetruy , A. Bohe , T. Hertog , D. A. Steer