Related papers: Cold Positrons from Decaying Dark Matter
We study the formation and properties of dark neutron stars in a scenario where dark matter is made up of (heavy) dark baryons in a sequestered copy of the MSSM. This scenario naturally explains the coincidence of baryonic and dark matter…
We observe that photon cooling after big bang nucleosynthesis (BBN) but before recombination can remove the conflict between the observed and theoretically predicted value of the primordial abundance of $^7$Li. Such cooling is ordinarily…
The hypothesis that neutrons might decay into dark matter is explored using neutron stars as a testing ground. It is found that in order to obtain stars with masses at the upper end of those observed, the dark matter must experience a…
The observed angular profile of the 511-keV photon excess from the Milky Way galactic center can allow us to select among combinations of various dark matter and other positron production mechanisms with various models for the dark matter…
A different reason for the apparent weakness of the gravitational interaction is advanced, and its consequences for Hawking evaporation of a Schwarzschild black hole are investigated. Proceeding from some fundamental thermodynamic…
We study the phase transition of a system of self-gravitating neutrinos in the presence of a large radiation density background in the framework of the Thomas-Fermi model. We show that, by cooling a non-degenerate gas of massive neutrinos…
The decay of light bosonic dark matter particles can produce a bright electron/positron ($e^+e^-$) flux that can be strongly constrained by local Voyager observations of the direct $e^+e^-$ flux, as well as 511 keV Line and X-ray continuum…
The astronomical dark matter is an essential component of the Universe and yet its nature is still unresolved. It could be made of neutral and massive elementary particles which are their own antimatter partners. These dark matter species…
The large gap between a galactic dark matter subhalo's velocity and its own gravitational binding velocity creates the situation that small subhalos can be evaporated before dark matter thermalize with baryons due to the low binding…
Cold dark matter (CDM) models predict small-scale structure in excess of observations of the cores and abundance of dwarf galaxies. These problems might be solved, and the virtues of CDM models retained, even without postulating {\it ad…
Dark matter that gets captured in the Sun may form positronium-like bound states if it self-interacts via light dark photons. In this case, dark matter can either annihilate to dark photons or recombine in bound states which subsequently…
The stability of particles in the cosmic soup is an important property that can affect the cosmic evolution. In this work, we update the constraints on the decaying cold dark matter scenario, when the decay products are effectively…
A triplet dark matter candidate from thermal leptogenesis is considered with building a model. The model is based on the standard two Higgs doublet model and seesaw mechanism with Higgs triplets. The parameters (couplings and masses) are…
Our Galaxy hosts the annihilation of a few $\times 10^{43}$ low-energy positrons every second. Radioactive isotopes capable of supplying such positrons are synthesised in stars, stellar remnants, and supernovae. For decades, however, there…
Although Planck data supports the standard \Lambda CDM model, it still allows for the presence of Dark Radiation corresponding up to about half an extra standard neutrino species. We propose a scenario for obtaining a fractional "effective…
In the framework of the Thomas-Fermi model at finite temperature, we show that a cooling nondegenerate gas of massive neutrinos will undergo a phase transition in which quasi-degenerate supermassive neutrino stars are formed through…
There is plenty of evidence that most matter in the Universe is dark (non-luminous). Particle physics offers several possible explanations. In this talk I focus on cold dark matter; the most promising candidates are then axions and the…
Optically thin cooling gas at most temperatures above 30K will make condensations by pressure pushing material into cool dense regions. This works without gravity. Cooling condensations will flatten and become planar/similarity solutions.…
When the vacuum like energy of the Higgs potential within the standard model undergoes electroweak phase transition, an influx of entropy into the primordial plasma can lead to a significant dilution of frozen out dark matter density that…
We analyse SPI/INTEGRAL data on the 511 keV line from the Galactic Centre, accumulated over ~6 years of observations. We decompose the X-ray and soft gamma-ray emission of the central part of the Milky Way into a relatively compact "Bulge"…