相关论文: Cosmic Strings in an Open Universe: Quantitative E…

It is well known that the $\Lambda$-term is a very good candidate for the smooth component of the universe since it resolves the so-called ``$\Omega$-problem'' giving, at the same time, sufficiently large age of the universe. However, the…

We consider the quantum birth of a hot FRW universe from a vacuum-dominated quantum fluctuation with admixture of radiation and strings, which correspond to quantum tunnelling from a discrete energy level with a non-zero temperature. The…

We investigate the contribution of cosmic string loops to the Cosmic Microwave Background (CMB) anisotropies. This is done by extending the Unconnected Segment Model (USM) to include the contribution of the cosmic string loops created…

Cosmic strings are generically predicted in many extensions of the Standard Model of particle physics. We propose a new avenue for detecting cosmic strings through their effect on the filamentary structure in the cosmic web. Using…

Cosmic strings formed during inflation are expected to be either diluted over super-Hubble distances, i.e., invisible today, or to have crossed our past light cone very recently. We discuss the latter situation in which a few strings…

We argue that cosmic strings with high winding numbers generally form in first-order gauge symmetry breaking phase transitions, and we demonstrate this using computer simulations. These strings are heavier than single-winding strings and…

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…

We investigate the effects of cosmological expansion on the spectrum of small-scale structure on a cosmic string. We simulate the evolution of a string with two modes that differ in wavelength by one order of magnitude. Once the short mode…

Recent measurements of the cosmic microwave background (CMB) anisotropies by BOOMERANG and MAXIMA collaborations have tightened the observational constraints on theories of structure formation. They disagree with the predictions of…

We investigate the contribution made by small loops from a cosmic string network as seeds for large-scale structure formation. We show that cosmic string loops are highly correlated with the long-string network on large scales and therefore…

Brane inflation in superstring theory predicts that cosmic strings (but not domain walls or monopoles) are produced towards the end of the inflationary epoch. Here, we discuss the production, the spectrum and the evolution of such cosmic…

Using an analytic model we show that the predictions of the cosmic string model for the peculiar velocities and the microwave background (MBR) anisotropy depend on similar combinations of string evolution parameters. Normalizing from the…

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 analyse the large-scale coherence of the CMB anisotropy field with non-gaussian initial conditions usind 2-point function of the power fluctuations in the wavelet space. Employing the multivariate Edgeworth expansion (MEE) we constrain…

We examine the effects of cosmic strings on structure formation and on the ionization history of the universe. While Gaussian perturbations from inflation are known to provide the dominant contribution to the large scale structure of the…

Cosmic strings can be created in the early universe during symmetry-breaking phase transitions, such as might arise if the gauge structure of the standard model is extended by additional U(1) factors at high energies. Cosmic strings present…

We investigate the properties of global cosmic string networks as a function of the ratio of string tension to Goldstone-field coupling, and as a function of the Hubble damping strength. Our results show unambiguously that the string…

In the context of the pre-big bang scenario the large-scale CMB anisotropy can be seeded by a primordial background of very light (or massless) axion fluctuations. In that case the slope of the temperature anisotropy spectrum, allowed by…

The number of cosmic strings in the observable universe is relevant in determining the probability of detecting such cosmic defects through their gravitational signatures. In particular, we refer to the observation of gravitational lensing…

An analytic model of long string network evolution, recently developed by the authors, is presented in detail, and modified to describe string loop evolution. By treating the average string velocity, as well as the characteristic…