Related papers: Vacuum polarization near cosmic string in RS2 bran…
A massive scalar field is quantized in the background of a cosmic string which is generalized to a static flux-carrying codimension-2 brane in the locally flat multidimensional space-time. We find that the finite energy-momentum tensor is…
In the light of recent work which suggests that structure formation by cosmic strings in a critical matter density universe requires large biases, we discuss the effects of reducing the matter density. Using a full linear Einstein-Boltzmann…
Motivated by the example of the superconducting cosmic string which can be a physical representation of a straight wire carrying a steady current, we derive in this case the explicit expressions of the induced vector potential, current…
The self-tuning brane scenario is an attempt to solve the cosmological constant problem in the context of extra dimensions. Rather than making the vacuum energy small, this approach proceeds by removing the gravitational effect of vacuum…
This paper is dedicated to investigate an astrophysical method to obtain the new dynamics generated by extra dimensions as well as bounds for the brane tension. Using the modified Einstein equations in the brane with a vanishing non-local…
False vacuum decay typically proceeds via the nucleation of spherical bubbles of true vacuum, described by $O(4)$ symmetric field configurations in Euclidean time. In this work, we investigate how the presence of cosmic strings can catalyze…
Brane inflation is a specific realization of the inflationary universe scenario in the early universe within the brane world framework in string theory. The naturalness and robustness of this realistic scenario is explained. Its predictions…
Cosmic strings are predicted in many models beyond the Standard Model of particle physics. In models which admit strings, a network of strings will inevitably be formed in a phase transition in the early universe and will persist to the…
The relativistic charged spinor matter field is quantized in the background of a straight cosmic string with nonvanishing transverse size. The most general boundary conditions ensuring the impossibility for matter to penetrate through the…
The main goal of string phenomenology is to find realistic models of particle physics and cosmology within string theory. Dark bubble cosmology is an alternative to string compactifications, where our universe lives on a bubble expanding in…
The aim of this talk is to provide non-experts with a brief and elementary introduction on the field of extra dimensions. The main motivation for extra dimensions relies on the more fundamental string theories that predict ten (or eleven)…
The vacuum expectation values of the energy--momentum tensor and the fermionic condensate are analyzed for a massive spinor field obeying the MIT bag boundary condition on a cylindrical shell in the cosmic string spacetime. Both regions…
We calculate the gravitational radiation emitted by an infinite cosmic string with two oppositely moving wave-trains, in the small amplitude approximation. After comparing our result to the previously studied cases we extend the results to…
We propose a string-inspired model which correlates several aspects of particle physics and cosmology. Inspired by the flat directions and the absence of adjoint Higgs representations found in typical string models, we consider a no-scale…
The space-time dimensions transverse to a static straight cosmic string with a sufficiently large tension (supermassive cosmic strings) are compact and typically have a singularity at a finite distance form the core. In this paper, we…
A weak-field solution of Einstein's equations is constructed. It is generated by a circular cosmic string revolving in its plane about the centre of the circle. (The revolution is introduced to prevent the string from collapsing.) This…
We study dynamics of a cosmic string in a metastable brane configuration in Type IIA string theory. We first discuss a decay process of the cosmic string via a fuzzy brane (equivalently bubble/string bound state) by neglecting gravitational…
We explore the kinematical effect of having extra dimensions on the gravity wave emission from cosmic strings. Additional dimensions both round off cusps, and reduce the probability of their formation. We recompute the gravity wave burst,…
In a toy model we derive the gravitational equation on a self-gravitating curved D-brane. The effective theory on the brane is drastically changed from the ordinal Einstein equation. The net cosmological constant on the brane depends on a…
We investigate the evolution of small perturbations around black strings and branes which are low energy solutions of string theory. For simplicity we focus attention on the zero charge case and show that there are unstable modes for a…