Related papers: Antimatter in the Universe : Constraints from Gamm…
The existence of antimatter domains in baryon asymmetrical Universe can appear as the cosmological consequence of particle theory in inflationary models with non-homogeneous baryosynthesis. Such a domain can survive in the early Universe…
Two of the most compelling issues facing astrophysics and cosmology today are to understand the nature of the dark matter that pervades the universe and to understand the apparent absence of cosmological antimatter. For both issues,…
We review observational evidence for a matter-antimatter asymmetry in the early universe, which leads to the remnant matter density we observe today. We also discuss observational bounds on the presence of antimatter in the present day…
A possible existence of cosmologically large domains of antimatter or astronomical ``anti-objects'' is discussed. A brief review of different scenarios of baryogenesis predicting a noticeable amount of antimatter is given. Though both…
The existence of macroscopic regions with antibaryon excess in the baryon asymmetric Universe with general baryon excess is the possible consequence of practically all models of baryosynthesis. Diffusion of matter and antimatter to the…
We know from experimental high energy physics that whenever matter is created, an equal amount of antimatter is also created. However, we live in a large region of the universe where the antimatter can not constitute more than a very small…
The whole set of astrophysical data indicates that our Universe is globally baryon asymmetrical. Nevertheless a possibility of existence of relatively small amount of sufficiently large antimatter regions is not excluded. Such regions can…
Models of baryogenesis which may lead to astronomically significant amount of antimatter in the universe are reviewed. Observational features are briefly discussed.
The Galactic positrons, as observed by their annihilation gamma-ray line at 0.511 MeV, are difficult to account for with astrophysical sources. It has been proposed that they are produced instead by dark matter annihilation or decay in the…
The existence of macroscopic objects from antimatter (antistars) is envisaged in some models of baryogenesis. Searches for antistars has been usually carried out in gamma-rays through hadronic annihilation of matter. In astrophysically…
A model which leads to abundant antimatter objects in the Galaxy (anti-clouds, anti-stars, etc) is presented. Observational manifestations are analyzed. In particular, the model allows for all cosmological dark matter to be made out of…
We ask whether the universe can be a patchwork consisting of distinct regions of matter and antimatter. We demonstrate that, after recombination, it is impossible to avoid annihilation near regional boundaries. We study the dynamics of this…
The possibility of creation of cosmologically significant antimatter are analyzed in different scenarios of baryogenesis. It is argued that there may exist plenty of antimatter even in our Galaxy. Possible forms of antimatter objects and…
We consider consequences of hypothetical existence of baryo-dense stars created in the very early universe within an extension of Affleck-Dine scenario of baryogenesis. New constraints on the possible number of compact antimatter objects…
The discovery of a single anti-helium nucleus in the cosmic ray flux would definitely point toward the existence of stars and even of entire galaxies made of anti-matter. The presence of anti-nuclei in cosmic rays has actually profound…
We offer a survey of the matter-antimatter evolution within the primordial Universe. While the origin of the tiny matter-antimatter asymmetry has remained one of the big questions in modern cosmology, antimatter itself has played a large…
Cosmic rays at the Earth include a secondary component originating in collisions of primary particles with the diffuse interstellar gas. The secondary cosmic rays are relatively rare but carry important information on the Galactic…
Observational signatures of existence of antimatter objects in the Galaxy are discussed. We focus on point-like sources of gamma radiation, diffuse galactic gamma ray background and anti-nuclei in cosmic rays.
A number of signals involving charged cosmic rays and high-energy photons have been interpreted as being due to annihilating dark matter. This article provides an overview of the experimental evidence and discusses in particular detections…
High energy gamma-rays and neutrinos can be produced both by the annihilation and by the possible slow decay of dark matter particles. We discuss the fluxes and spectra of such secondaries produced by dark matter particles in the universe…