Related papers: Probing the Dark Dimension with Auger data
The discovery of the accelerating universe indicates strongly the presence of a scalar field which is not only expected to solve today's version of the cosmological constant problem, or the fine-tuning and the coincidence problems, but also…
In this work we consider a dark matter candidate described by an ultralight vector field, whose mass is in principle in the range $H_{\rm{eq}}\sim 10^{-28}\rm{eV}\ll m< \rm{eV}$. The homogeneous background vector field is assumed to point…
The energy density of the universe today may be dominated by the vacuum energy of a slowly rolling scalar field. Making a quantum expansion around such a time dependent solution is found to break fundamental symmetries of quantum field…
The standard assumption about the influence of the turbulent intergalactic magnetic field (IGMF) on the images of ultra-high-energy cosmic rays (UHECR) sources is that the latter are formed in a random walk mode in the deflection angle. As…
The existence of dark energy is essential to explain the cosmic accelerated expansion. We consider a homogenous interacting tachyonic scalar field as a possible candidate for the dynamical dark energy. The interaction between the tachyonic…
The spectra of BL Lac objects and Fanaroff-Riley I radio galaxies are commonly explained by the one-zone leptonic synchrotron self-Compton (SSC) model. Spectral modeling of correlated multiwavelength data gives the comoving magnetic field…
In the very last years, cosmological models where the properties of the dark components of the Universe - dark matter and dark energy - are accounted for by a single "dark fluid" have drawn increasing attention and interest. Amongst many…
We study constraints imposed by two proposed string Swampland criteria on cosmology. These criteria involve an upper bound on the range traversed by scalar fields as well as a lower bound on $|\nabla_{\phi} V|/V$ when $V >0$. We find that…
We develop the statistical methods for comparing two sets of arrival directions of cosmic rays in which the two-dimensional distribution of arrival directions is reduced to the one-dimensional distributions so that the standard…
A mildly inhomogeneous universe with a cosmological constant may look like it contains evolving dark energy. We show that could be the case by modelling the inhomogeneities and their effects in three different ways: as clumped matter…
As observational evidence increasingly consolidates the case for a cosmological constant being the source of the Universe's accelerated expansion, the question whether, and if so, how well, future experiments could detect deviations from…
The concordance (LambdaCDM) model reproduces the main current cosmological observations assuming the validity of general relativity at all scales and epochs, the presence of cold dark matter, and of a cosmological constant, equivalent to a…
(abridged) The Pierre Auger Collaboration has reported 27 Ultra-High Energy Cosmic Ray Events (UHECRs) with energies above 56 EeV and well determined arrival directions as of 2007 August 31. They find that the arrival directions are not…
We propose a framework for the low-energy realization of supersymmetry which is very predictive, but differs radically in its phenomenological implications from the supersymmetric Standard Model (minimal or otherwise). The proposal consists…
Planck scale physics represents a future challenge, located between particle physics and general relativity. The Planck scale marks a threshold beyond which the old description of spacetime breaks down and conceptually new phenomena must…
Cosmological observations of the recent universe suggest that dark energy equation of state parameter $w$ is growing with time, departing from a cosmological constant for which $w=-1$. Standard quintessence models allow for a varying…
The mystery of the Dark energy is not just its smallness. The extreme fine tuning of its density in the Early Universe such that it permits galaxy formation before creating a new inflationary epoch is its other unexplained aspect. Here we…
The reason for the present accelerated expansion of the Universe stands as one of the most profound questions in the realm of science, with deep connections to both cosmology and fundamental physics. From a cosmological point of view,…
The Pierre Auger Observatory is the world's largest detector of ultra--high energy cosmic rays (UHECRs). It uses an array of fluorescence telescopes and particle detectors at the ground to obtain detailed measurements of the energy…
The Hubble expansion of the Universe is considered in the classical limit of a Big Bang quantum cosmology. In an IR-consistent coupling to the the bare cosmological constant, we infer a dark energy as a relic of the Big Bang by loss of…