Related papers: Effects of Cosmic Strings on Free Streaming

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…

Current data exclude cosmic strings as the primary source of primordial density fluctuations. However, in a wide class of inflationary models, strings can form at later stages of inflation and have potentially detectable observational…

After their generation, cosmological backgrounds of gravitational waves propagate nearly freely but for the expansion of the Universe and the anisotropic stress of free-streaming particles. Primordial signals -- both that from inflation and…

We investigate scaling and correlations of the energy and momentum in an evolving network of cosmic strings in Minkowski space. These quantities are of great interest, as they must be understood before accurate predictions for the power…

We describe cosmic F--term strings with exponentially small tension which are D3 branes wrapped on deformed $A_3$ singularities. We show that brane instanton effects which can be calculated after a geometric transition give rise to an…

This paper discusses the gravitational scattering of a straight, infinitely long test cosmic string by a black hole. We present numerical results that probe the two-dimensional parameter space of impact parameter and initial velocity and…

We report that axions and photons exhibit instability in the presence of cosmic strings that are carrying magnetic flux in their core. The strength of the instability is determined by the symmetry breaking scale of the cosmic string theory.…

In the paper Phys. Lett. B614 (2005), 140-142, F. Nasseri shows that the values of the fine structure constant reduces due to the presence of a cosmic string. In this comment I want to point out that this conclusion is not completely…

We present a study of open inflation cosmological scenarios in which cosmic strings form betwen the two inflationary epochs. It is shown that in these models strings are stretched outside the horizon due to the inflationary expansion but…

The main goal of this work is to pursue an investigation of cosmic string configurations focusing on possible consequences of the Lorentz-symmetry breaking by a background vector. We analyze the possibility of cosmic strings as a viable…

We study the behaviour of a non-relativistic quantum particle interacting with different potentials, in the background spacetime generated by a cosmic string. We find the energy spectra for the quantum systems under consideration and…

Using the formalism developed in a previous paper we analyze the cosmological implications of our conclusions concerning the scaling behaviour of a network of cosmic strings, in particular the idea that once gravitational back-reaction…

We compute the linear power spectrum of cosmic string sedeed fluctuations in the context of neutrinos with a strong self-interaction and show that it is very similar to that obtained in the context of `normal' neutrinos. We compare our…

We want to find the cosmological constant influence on cosmic microwave background (CMB) temperature due to moving linear cosmic strings. Considering the space-time metric of a linear cosmic string in an accelerated expanding universe, the…

Cosmic strings, topological defects predicted by high-energy theories, may contribute to the late-time expansion of the Universe, effectively mimicking dynamical dark energy. We investigate four phenomenological extensions of the…

We study here how the presence of non-zero matter density and a cosmological constant could affect the observation of gravitational waves in Pulsar Timing Arrays. Conventionally, the effect of matter and cosmological constant is included by…

Effects of a generalized dark energy fluid is investigated on cosmic density fluctuations such as cosmic microwave background. As a general dark energy fluid, we take into consideration the possibility of the anisotropic stress for dark…

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…

A novel mechanism to produce a cosmic network of fundamental superstrings based on a time-varying string tension has been recently proposed. It has been found that fundamental superstrings can grow in a kinating background driven by the…

The possibility of the cosmic string creation by the vacuum fluctuations of quantum fields in the self-consistent semiclassical theory of gravity is discussed. We use the approximate method for obtaining vacuum expectation value of the…