Related papers: Structures in the Mirror Universe
We propose a novel class of compact dark matter objects in theories where the dark matter consists of multiple sectors. We call these objects $N$-MACHOs. In such theories neither the existence of dark matter species nor their extremely weak…
Structure formation creates high temperature and density regions in the Universe that allow the conversion of matter into more stable states, with a corresponding emission of relativistic matter and radiation. An example of such a mechanism…
Dark matter freeze-in at stronger coupling is operative when the Standard Model (SM) bath temperature never exceeds the dark matter mass. An attractive feature of this scenario is that it can be probed by direct detection experiments as…
Mirror models lead to the possibility that neutron ($n$) can oscillate into its mirror partner ($n'$) inspiring several experimental searches for this phenomenon. The condition for observability of this oscillation is a high degree of…
If the preon structure of quarks, leptons and gauge bosons will be proved then in the Universe during relativistic phase transition the production of nonperturbative preon condensates has been occured collective excitations of which are…
The physics of the mysterious and stealthy neutrino is at the heart of many phenomena in the cosmos. These particles interact with matter and with each other through the aptly named weak interaction. At typical astrophysical energies the…
We review the insufficiencies of the hypothesis that neutrinos and quarks are physical particles in our spacetime; we introduce the hypothesis that the energy and spin needed for the synthesis of the neutron inside stars originate either…
There are six main things which any non-baryonic dark matter theory should endeavour to explain: (1) The basic dark matter particle properties [mass, stability, darkness]; (2) The similarity in cosmic abundance between ordinary and…
We minimally extend the SM with a Z$_2$ symmetric potential containing a single scalar field, serving as our inflaton with a quartic self-coupling. In the model we have symmetry breaking in both sectors, and with the addition of an…
The nonbaryonic dark matter of the Universe is assumed to consist of new stable forms of matter. Their stability reflects symmetry of micro world and mechanisms of its symmetry breaking. Particle candidates for cosmological dark matter are…
Following the approach of Julien Lesgourgues [astro-ph/0409426], we analyze the mathematical structure of the time co-ordinate of present day cosmological models, where these models include a cosmological constant term to account for the…
Neutron stars are some of the densest manifestations of massive objects in the universe. They are ideal astrophysical laboratories for testing theories of dense matter physics and provide connections among nuclear physics, particle physics…
The standard model of particle physics is extended by adding a purely neutrinophilic dark sector. It is shown that theories which accommodate standard model neutrinos as dark radiation are resurrected. Sterile neutrinos bridge the visible…
We study chiral symmetry structure at finite density and temperature in the presence of external magnetic field and gravity, a situation relevant in the early Universe and in the core of compact stars. We then investigate the dynamical…
We propose a new freeze-in dark matter candidate which feebly couples to the standard model charged leptons. The feeble interactions allow it (i) to freeze-in from the Standard Model thermal bath with its relic density being either a…
From higher dimensional theories, e.g. string theory, one expects the presence of non-minimally coupled scalar fields. We review the notion of conformal frames in cosmology and emphasize their physical equivalence, which holds at least at a…
Asymmetric reheating is a generic requirement for models of dark sectors with light species, but its implementation is usually in tension with unique phenomenologies otherwise possible in compelling theories containing dark copies of the…
The baryon-dark matter coincidence is a long-standing issue. Interestingly, the recent observations suggest the presence of dark radiation, which, if confirmed, would pose another coincidence problem of why the density of dark radiation is…
We examine the possibility of "soft cosmology", namely small deviations from the usual framework due to the effective appearance of soft-matter properties in the Universe sectors. One effect of such a case would be the dark energy to…
Cooling forces result from the retarded dipole interaction between an illuminated particle and its reflection. For a one-dimensional example, we find cooling times of milliseconds and limiting temperatures in the millikelvin range. The…