相关论文: Dark Matter Annihilations in the Causal Diamond
In this paper we develop a Markov Chain Monte Carlo code to study the dark matter properties in interpreting the recent observations of cosmic ray electron/positron excesses. We assume that the dark matter particles couple dominantly to…
We show that the relic abundance of the minority component of asymmetric dark matter can be very sensitive to the expansion rate of the Universe and the temperature of transition between a non-standard pre-Big Bang Nucleosynthesis…
We discuss how entropy bounds, which are not respected in the standard cosmology, constrain the parameters of a previously suggested cosmology with a finite total mass. In that alternative cosmology the matter density was postulated to be a…
The dark matter content of the Universe is likely to be a mixture of matter and antimatter, perhaps comparable to the measured asymmetric mixture of baryons and antibaryons. During the early stages of the Universe, the dark matter particles…
Cosmic microwave background (CMB) constraints on dark matter annihilation are a uniquely powerful tool in the quest to understand the nature of dark matter. Annihilation of dark matter to Standard Model particles between recombination and…
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…
We show that dark matter with certain minimal properties can convert the majority of baryons in galaxies to black holes over hundred trillion year timescales. We argue that this has implications for cosmologies which propose that new…
We review and clarify ideas proposed many years ago for understanding cosmology in a holographic framework. The basic strategy is to use Jacobson's\cite{ted95} identification of Einstein's equations with the hydrodynamic equations of the…
Two general problems arise when interpreting the recent cosmic ray data as signals of Dark Matter (DM) annihilation: (i) the required cross section is too large by O(100), and (ii) the annihilation products seem to be mostly leptonic. We…
The decay and annihilation cross sections of dark matter particles may depend on the value of a chameleonic scalar field that both evolves cosmologically and takes different values depending on the local matter density. This possibility…
We study the emergence of entropy in gravitational production of dark matter particles, ultra light scalars minimally coupled to gravity and heavier fermions, from inflation to radiation domination (RD). Initial conditions correspond to…
The relic abundance of particle and antiparticle dark matter (DM) need not be vastly different in thermal asymmetric dark matter (ADM) models. By considering the effect of a primordial asymmetry on the thermal Boltzmann evolution of coupled…
Recent measurements of cosmic ray leptons by PAMELA, ATIC, HESS and Fermi revealed interesting excesses. Many authors suggested particle Dark Matter (DM) annihilations could be at the origin of these effects. In this paper, we critically…
Entanglement entropy in causal sets offers a fundamentally covariant characterisation of quantum field degrees of freedom. A known result in this context is that the degrees of freedom consist of a number of contributions that have…
The Chinese satellite Wukong, also known as the DArk Matter Particle Explorer (DAMPE), has released its observation data of the cosmic ray (CR) electrons and positrons. The data shows an excess in the energy spectrum up to TeV energy, and…
We study cosmological perturbations in the context of an interacting dark energy model, in which the cosmological term decays linearly with the Hubble parameter, with concomitant matter production. A previous joint analysis of the…
The detection of the theoretically expected dark matter is central to particle physics and cosmology. Current fashionable supersymmetric models provide a natural dark matter candidate which is the lightest supersymmetric particle (LSP). The…
In dark matter (DM) cosmology, the central question is how the present-day density of DM is generated from some initial conditions in the early universe. Different production mechanisms of DM are instrumental in probing DM microphysics in…
The Standard Cosmological Model has experienced tremendous success at reproducing observational data by assuming a universe dominated by a cosmological constant and dark matter in a flat geometry. However, several studies, based on local…
Dark Matter (DM) density is reduced if entropy production takes place after DM particles abundance is frozen out in the early universe. We study a possibility of such reduction due to entropy production in the electroweak phase transition…