Abstract ALP domain walls without strings may be formed in the early Universe. We point out that such lead to both isotropic and anisotropic birefringence of cosmic microwave background (CMB) polarization, which reflects spatial configuration at recombination. The polarization plane CMB photon coming from each is either not rotated all or by a fixed angle. For following scaling solution, charac...

Towards the end of the brane inflationary epoch in the brane world, cosmic strings (but not texture, domain walls or monopoles) are copiously produced during brane collision. These cosmic strings are Dp-branes with (p−1) dimensions compactified. We elaborate on this prediction of the superstring theory description of the brane world. Using the data on the temperature anisotropy in the cosmic mi...

Probing cosmic large scale structure on the basis of X-ray observations puts particular emphasis on the densest regions within the global matter distribution, the rich clusters of galaxies. Understanding the relationship between the cluster distribution and the underlying matter distribution is therefore a key element in any assessment of cosmic structure on the basis of samples of X-ray select...

The gravitational field of a global monopole in the context of Brans-Dicke theory of gravity is investigated. The space-time and the scalar field generated by the monopole are obtained by solving the field equations in the weak field approximation. A comparison is made with the corresponding results predicted by General Relativity. Electronic address: [email protected] 1 Monopoles resulting ...

Primordial black holes(PBHs) can be produced from collapsing cosmic defects such as domain walls and strings. We show how PBHs are produced in monopole-string networks considering two types of monopole-string networks.

We study cosmological implications of the duality (PSL(2,Z)) invariant potential for the compactification radius T , arising in a class of superstring vacua. We show that in spite of having only one minimum in the fundamental domain of the T field there are two types of non-supersymmetric domain walls: one is associated with the discrete Peccei-Quinn symmetry T → T + i, analogous to the axionic...

Axions have for some time been considered a plausible candidate dark matter. They can be produced through misalignment, but it has argued that when inflation occurs before Peccei-Quinn transition, appreciable production result from cosmic strings. This the subject of extensive simulations. But there are reasons to skeptical about possible role axion We review and elaborate on these questions, a...