Related papers: Model Dependence of Baryon Decay Enhancement by Co…
In generic models for grand unified theories(GUT), various types of baryon number violating processes are expected when quarks and leptons propagate in the background of GUT strings. On the other hand, in models with large extra dimensions,…
We study the scenario of electroweak baryogenesis mediated by nonsuperconducting cosmic strings. This idea relies upon electroweak symmetry being restored in a region around the core of the topological defect so that, within this region,…
The electroweak symmetry is unbroken in the core of cosmic strings originating from a symmetry breaking at an energy higher than the electroweak scale $\eta_{EW}$. The dynamics of such strings may generate a baryon asymmetry below the…
The string breaking phenomenon in QCD can be studied using the gauge/string duality. In this approach, one can make estimates of some of the string breaking distances at non-zero temperature and baryon chemical potential. These point…
We have studied numerically the evolution and decay of axion strings. These global defects decay mainly by axion emission and thus contribute to the cosmological axion density. The relative importance of this source relative to misalignment…
Based on the mechanism of cusp production on long cosmic strings, the baryon asymmetry caused by cusp annihilation has been calculated. The result is compatible with observation and stronger than the results from loops.
The amount of baryon asymmetry generated by the electroweak strings at a rough estimate is smaller than that generated by the bubble expansion since the collapsing strings cannot cover the whole volume of the universe. However, the…
Cosmic strings are a type of cosmic defect formed by a symmetry-breaking phase transition in the early universe. Individual strings would have gathered to build a network, and their dynamical motion would induce scalar--, vector-- and…
If the Universe underwent a cosmic phase transition, it may have left behind a network of cosmic strings. When these strings arise from the breaking of a gauge symmetry, their decay produces a significant stochastic background of…
Proton decay is a smoking gun signature of Grand Unified Theories (GUTs). Searches by Super-Kamiokande have resulted in stringent limits on the GUT symmetry breaking scale. The large-scale multipurpose neutrino experiments DUNE,…
A synthesis of previous work done on the microscopic structure of cosmic strings in realistic models is made and reveals that strings are expected to be not only superconducting in the sense of Witten, but also generically current-carrying,…
It has been speculated that cosmic string networks could produce ultra-high energy cosmic rays as a by-product of their evolution. By making use of recent work on the evolution of such networks, it will be shown that the flux of cosmic rays…
We construct field configurations that interpolate between string background states of differing baryon number. Using these configurations we estimate the effect of the background fields on the energy barrier separating different vacua. In…
We study the stability of extra dimensions in string gas cosmology at late times. Vacuum energy and, interestingly, baryons lead to decompactification after they become dynamically important. The string gas can stabilise the effect of…
A novel mechanism for the production of a cosmic network of fundamental superstrings based on a time-varying string tension has been recently proposed in the context of a kinating background driven by the volume modulus of string…
We explore the viability of baryogenesis from light scalar decays after the electroweak phase transition. A minimal model of this kind is constructed with new CP violating interactions involving a heavy fourth family. The departure from…
The nucleon decay is a significant phenomenon to verify grand unified theories (GUTs). For the precise prediction of the nucleon lifetime induced by the gauge bosons associated with the unified gauge group, it is important to include the…
Cosmic strings, theoretical one-dimensional topological defects from the early universe, provide a valuable opportunity for exploring dark matter (DM) production and gravitational wave (GW) emission. Our study investigates the production of…
The fluid equations for the baryon-electron system in an expanding universe are derived from the Boltzmann equation. The effect of the Compton interaction is taken into account properly in order to evaluate the photon-electron collisional…
I report on a critical analysis of the scenario of electroweak baryogenesis mediated by nonsuperconducting cosmic strings. This mechanism relies upon electroweak symmetry restoration in a region around cosmic strings, where sphalerons would…