Related papers: Can Early Dark Energy be Detected in Non-Linear St…
We investigate our knowledge of early universe cosmology by exploring how much additional energy density can be placed in different components beyond those in the $\Lambda$CDM model. To do this we use a method to separate early- and…
Understanding the nature of the dark energy is one of the most important task in cosmology. In principle several cosmological observations can be used to discriminate amid a static cosmological constant contribution and a dynamical…
At early times dark matter has a thermal velocity dispersion of unknown amplitude which, for warm dark matter models, can influence the formation of nonlinear structure on observable scales. We propose a new scheme to simulate cosmologies…
Composite dark matter is a natural setting for implementing inelastic dark matter - the O(100 keV) mass splitting arises from spin-spin interactions of constituent fermions. In models where the constituents are charged under an axial U(1)…
Dark energy and dark matter constitute 95% of the observable Universe. Yet the physical nature of these two phenomena remains a mystery. Einstein suggested a long-forgotten solution: gravitationally repulsive negative masses, which drive…
By means of N-body simulations, we study early structure formation in the presence of a scaling distribution of cosmic string loops. Cosmic string loops dominate the high redshift halo mass function while the fluctuations seeded by the…
In this paper we revisit the issue of determining the oscillating primordial scalar power spectrum and oscillating equation of state of dark energy from the astronomical observations. By performing a global analysis with the Markov Chain…
Current cosmological data exhibit a tension between inferences of the Hubble constant, $H_0$, derived from early and late-universe measurements. One proposed solution is to introduce a new component in the early universe, which initially…
Minimal atomic dark matter with its distinctive cooling mechanisms offers an instructive framework for understanding the potential impact of dark matter on small-scale structure formation and early cosmology. The model consists of two…
The Cold Dark Matter (CDM) model for galaxy formation predicts that a significant fraction of mass in the dark matter haloes that surround L L* galaxies is bound in substructures of mass 1E4-1E7Msun. The number of observable baryonic…
We study the growth of matter perturbations beyond the linear level in cosmologies in which the dark energy has a variable equation of state. The non-linear corrections result in shifts in the positions of the maximum, minima and nodes of…
In the last year, several pieces of evidence have pointed to a possible deviation from the standard cosmological model, $\Lambda$CDM. The recent work by the Dark Energy Survey (DES) collaboration reports a preference in the ballpark of…
As one of the fundamental unknowns of our Universe, the mass of dark matter remains to be a topic of great interest. We consider the possibility of a time-variation of the dark matter mass. We study the cosmological constraints on a model…
Among the possible alternatives to the standard cosmological model ($\Lambda$CDM), coupled Dark Energy models postulate that Dark Energy (DE), seen as a dynamical scalar field, may interact with Dark Matter (DM), giving rise to a…
We study the nonlinear growth of cosmic structure in different dark energy models, using large volume N-body simulations. We consider a range of quintessence models which feature both rapidly and slowly varying dark energy equations of…
The recent observational evidence for the current cosmic acceleration have stimulated renewed interest in alternative cosmologies, such as scenarios with interaction in the dark sector (dark matter and dark energy). In general, such models…
We present results of cosmological N-body hydrodynamic chemistry simulations of primordial structure growth and evolution in a scenario with warm dark matter (WDM) having a mass of 3 keV (thermal relic) and compare with a model consisting…
The gravitationally-driven evolution of cold dark matter dominates the formation of structure in the Universe over a wide range of length scales. While the longest scales can be treated by perturbation theory, a fully quantitative…
Dark energy is one of the mysteries of modern science. It is unlike any known form of matter or energy and has been detected so far only by its gravitational effect of repulsion. Owing to its effects being discernible only at very very…
The galaxy power spectrum is now a well-known tool of precision cosmology. In addition to the overall shape, baryon oscillations and the small-scale suppression of power by massive neutrinos capture complimentary information on cosmological…