Related papers: Big Bang and Heavy Particles
Galaxies represent the visible fabric of the Universe and there has been considerable progress recently in both observational and theoretical studies. The underlying goal is to understand the present-day diversity of galaxy forms, masses…
Bursts of weakly interacting particles such as neutrinos or even more weakly interacting particles such as wimps and gravitons from the very early universe would offer a much deeper ``look back time'' to early epochs than is possible with…
We speculate on some novel consequences possibly associated with a change of elementary particle constants with time. These concern the question as to whether particles reaching the earth from distant parts of the universe reflect their…
Galaxies represent the visible fabric of the Universe and there has been considerable progress recently in both observational and theoretical studies. The underlying goal is to understand the present-day diversity of galaxy forms, masses…
This paper presents a brief review of the current status of ultrahigh energy cosmic ray observations and discusses nearby starburst-like galaxies as their possible origin.
We examine some general astrophysical results which can be related to the hypothesis that very heavy, metastable particles constitute compact, very massive central entities in QSO's and the core of galaxies. The mass and lifetime have been…
Cosmic ray particles with energies in excess of 10**(20) eV have been detected. The sources as well as the physical mechanism(s) responsible for endowing cosmic ray particles with such enormous energies are unknown. This report gives a…
Experimental results on ultra-high-energy cosmic rays are briefly reviewed and their interpretation is discussed. The results related to principal observables (arrival directions, energies and composition) of primary particles of extended…
For a brief time in its early evolution the Universe was a cosmic nuclear reactor. The expansion and cooling of the Universe limited this epoch to the first few minutes, allowing time for the synthesis in astrophysically interesting…
The concordance of standard big bang nucleosynthesis theory and the related observations of the light element isotopes (including some new higher \he4 abundances) will be reviewed. Implications of BBN on chemical evolution, dark matter and…
The origin of the highest-energy cosmic rays remains a mystery. The lack of a high energy cutoff in the cosmic ray spectrum together with an apparently isotropic distribution of arrival directions have strongly constrained most models…
Of the light nuclides observed in the universe today, D, 3He, 4He, and 7Li are relics from its early evolution. The primordial abundances of these relics, produced via Big Bang Nucleosynthesis (BBN) during the first half hour of the…
Massive stars have a profound influence on the Universe, but their formation remains poorly understood. We review the current status of observational and theoretical research in this field, describing the various stages of an evolutionary…
In this brief note, we would like to point out that large-scale structures like galaxies and superclusters would arise quite naturally in the universe.
A brief review of standard big bang nucleosynthesis theory and the related observations of the light element isotopes is presented. Implications of BBN on chemical evolution and constraints on particle properties will also be discussed.
The expansion of our universe, when followed backward in time, implies that it emerged from a phase of huge density, the big bang. These stages are so extreme that classical general relativity combined with matter theories is not able to…
Preliminary remarks, theoretical scenarios, cosmological constraints, couplings of very heavy neutrinos, production mechanisms and detection, summary.
We discuss the corrections to the lifetime of unstable elementary particles in some models of doubly special relativity. We assume that the speed of light is invariant and that the position coordinates transform in such a way to ensure the…
Several aspects of mathematical astrobiology are discussed. It is argued that around the time of the origin of life the handedness of biomolecules must have established itself through an instability. Possible pathways of producing a certain…
We discuss some of the cosmological constraints on the evolution and persistence of life in the Universe and in hypothetical universes other than our own. We highlight the role played by the age and size of the universe, and discuss the…