Related papers: Dark Matter in a One-dimensional Universe
Dark matter coupled solely gravitationally can be produced through the decay of primordial black holes in the early universe. If the dark matter is lighter than the initial black hole temperature, it could be warm enough to be subject to…
A range of cosmological observations demonstrate an accelerated expansion of the Universe, and the most likely explanation of this phenomenon is a cosmological constant. Given the importance of understanding the underlying physics, it is…
Ultracompact minihalos would be formed if there are larger density perturbations ($0.0003 < \delta\rho/\rho < 0.3$) in the earlier epoch. The density profile of them is steeper than the standard dark matter halos. If the dark matter can…
We study the structure formation by investigating the spherical collapse model in the context of new agegraphic dark energy model in flat FRW cosmology. We compute the perturbational quantities $g(a)$, $\delta_{c}(z_{c})$, $\lambda(z_{c})$,…
The first phase of stellar evolution in the history of the universe may be Dark Stars, powered by dark matter heating rather than by fusion. Weakly interacting massive particles, which are their own antiparticles, can annihilate and provide…
Recently, a model of modified gravity plus single scalar field model was proposed, in which the scalar couples both to the standard Riemannian volume form given by the square root of the determinant of the Riemannian metric, as well as to…
On large cosmological scales, anisotropic gravitational collapse is manifest in the dark cosmic web. Its statistical properties are little known for alternative dark matter models such as fuzzy dark matter (FDM). In this work, we assess for…
A huge amount of good quality data converges towards the picture of a spatially flat universe undergoing the today observed phase of accelerated expansion. This new observational trend is commonly addressed as Precision Cosmology. Despite…
Clouds containing molecular dark matter in quantities relevant for star formation may exist in minihaloes of the type of cold dark matter included in many cosmological simulations or in the regions of some galaxies extending far beyond…
How is the universe organized on large scales? How did this structure evolve from the unknown initial conditions of a rather smooth early universe to the present time? The answers to these questions will shed light on the cosmology we live…
Astronomical observations from small galaxies to the largest scales in the universe can be consistently explained by the simple idea of dark matter. The nature of dark matter is however still unknown. Empirically it cannot be any of the…
Long-lived particles (LLPs) provide an interesting window into physics beyond the Standard Model, offering characteristic signatures at colliders and in cosmology. In this work, we investigate LLPs decays into dark matter. If the lifetime…
Using a single dilaton field, a unified model of the Universe is proposed, which evolves from the radiation-like dominance in the Big Bang, to the dark-matter-like dominance in the early Universe, to the coexistence of both dark-matter-like…
In this paper we examine aspects of primordial star formation in a gravitino warm dark matter universe with a cosmological constant. We compare a set of simulations using a single cosmological realization but with a wide range of warm dark…
Two extra dimensions of micron scale might simultaneously address the gauge and cosmological hierarchy problems. In our paper we examine various observational bounds in scenarios with one and two large extra dimensions, to see if they are…
Many independent high resolution simulations have indicated that the standard collisionless cold dark matter model does not reproduce the structure of observed present day galaxies well. Several possible solutions in the form of…
We perform a suite of cosmological simulations in the LCDM paradigm of the formation of the first structures in the Universe prior to astrophysical reheating and reionization (15<~z<200). These are the first simulations initialized in a…
If the Universe's energy density was dominated by a fast-rolling scalar field while the radiation bath was hot enough to thermally produce dark matter, then dark matter with larger-than-canonical annihilation cross sections can generate the…
A huge amount of good quality astrophysical data converges towards the picture of a spatially flat universe undergoing the today observed phase of accelerated expansion. This new observational trend is commonly addressed as Precision…
The cold dark matter may be in a meta-stable state and decays to other particles with a very long lifetime. If the decaying products of the dark matter are weakly interacting, e.g. neutrinos, then it would have little impact on…