Related papers: A Matter-Antimatter Universe?
We study the effects of dark matter annihilation during and after the cosmic recombination epoch on the cosmic microwave background anisotropy, taking into account the detailed energy deposition of the annihilation products. It is found…
In this work, we outline a new general relativistic cosmology. In this cosmology, the universe originates in the infinite past from sparsely distributed neutral matter and ends in the infinite future as a hot, relativistic plasma. The…
We review theories of Asymmetric Dark Matter (ADM), their cosmological implications and detection. While there are many models of ADM in the literature, our review of existing models will center on highlighting the few common features and…
Almost all models of the universe start by assuming that matter fields can be modelled as dust. In the real universe, however, matter is clumped into dense objects that are separated by regions of space that are almost empty. If we are to…
As one of the fundamental unknowns of our Universe, the mass of dark matter remains to be a topic of great interest. We consider the possibility of a time-variation of the dark matter mass. We study the cosmological constraints on a model…
Over the past few decades, a consensus picture has emerged in which roughly a quarter of the universe consists of dark matter. I begin with a review of the observational evidence for the existence of dark matter: rotation curves of…
The cosmological and astrophysical implications of a shadow matter model which could also have interesting experimental consequences are examined. The model has identical microphysics for both the ordinary and shadow worlds but requires a…
The LCDM standard model, although an excellent parametrization of the present cosmological data, requires two as yet unobserved components, Dark Matter and Dark Energy, for more than 95% of the Universe, and a high level of fine-tuning.…
We show that our Universe may be inhomogeneous on large sub-horizon scales without us being able to realise it. We assume that a network of domain walls permeates the universe dividing it in domains with slightly different vacuum energy…
One of the deepest unsolved puzzles of subatomic physics is why Nature prefers the left particles to the right ones. Mirror matter is an attempt to understand this mystery by assuming the existence of a "parallel''world where this…
The fine tuning of parameters required to reproduce our present day Universe suggests that our Universe may simply be a region within an eternally inflating super-region. Many other regions beyond our observable Universe would exist with…
Cosmology and astroparticle physics give strongest possible evidence for the incompleteness of the Standard Model of particle physics. Leaving aside misterious dark energy, which may or may not be just the cosmological constant, two…
In arXiv:2401.10954 I showed that, in the context of antigravity (i.e., matter and antimatter repel gravitationally), quark/lepton mass-energy is matter and antiquark/antilepton mass-energy is antimatter while the mass-energy of the…
Dark matter is a fundamental constituent of the universe, which is needed to explain a wide variety of astrophysical and cosmological observations. Although the existence of dark matter was first postulated nearly a century ago and its…
(Abridged) Present cosmological constraints and the absence of a direct detection and identification of any dark matter particle candidate leave room to the possibility that the dark sector of the Universe be actually more complex than it…
Modern cosmology successfully deals with the origin and the evolution of the Universe at large scales, but it is unable to completely answer the question about the nature of the fundamental objects that it is describing. As a matter of…
Nature abhors an infinity. The limits of general relativity are often signaled by infinities: infinite curvature as in the center of a black hole, the infinite energy of the singular big bang. We might be inclined to add an infinite…
Using gamma-ray data from observations of the Milky Way, Andromeda (M31), and the cosmic background, we calculate conservative upper limits on the dark matter self-annihilation cross section to a number of final states, over a wide range of…
Dark matter particles need not be completely stable, and in fact they may be decaying now. We consider this possibility in the frameworks of universal extra dimensions and supersymmetry with very late decays of WIMPs to Kaluza-Klein…
Matter -antimatter asymmetry, expected to be very large in the Universe, is rediscussed considering effects which might not have been considered enterely before and which can also be relevant for (high energy densities) relativistic heavy…