Related papers: Effective dark energy through spin-gravity couplin…
We consider cosmological models with dynamical dark energy (dDE) coupled to cold dark matter (CDM), while simultaneously allowing neutrinos to be massive. Using a MCMC approach, we compare these models with a wide range of cosmological data…
We propose a phenomenological model in which a non-minimal coupling between gravity and dark matter is present in order to address some of the apparent small scales issues of \lcdm model. When described in a frame in which gravity dynamics…
We present a unifying treatment of dark energy and modified gravity that allows distinct conformal-disformal couplings of matter species to the gravitational sector. In this very general approach, we derive the conditions to avoid ghost and…
While the standard $\Lambda$CDM model succeeds on large cosmological scales, it faces persistent small-scale challenges, including the core-cusp problem, the diversity of galaxy rotation curves, and the tight correlation between dark matter…
We study the coupled dark energy model constructed from the general conformal transformation in which the coefficient of the conformal transformation depends on both the scalar field and its kinetic term. Under this conformal…
In Cosmology, when dissipative effects are minimal, the energy content of the Universe can be effectively described as a sum of perfect fluids. Perfect fluid descriptions ensure thermal equilibrium since they equilibrate immediately.…
When CMB data are used to derive cosmological parameters, their very choice does matter: some parameter values can be biased if the parameter space does not cover the "true" model. This is a problem, because of the difficulty to parametrize…
We present a non-parametric, model-independent reconstruction of the cosmological background and perturbation dynamics in non-minimally coupled theories of gravity. Within the Effective Field Theory of dark energy framework, we reconstruct…
In the Horndeski's most general scalar-tensor theories the equations of scalar density perturbations are derived in the presence of non-relativistic matter minimally coupled to gravity. Under a quasi-static approximation on sub-horizon…
Coupled dark matter-dark energy scenarios are modeled via a dimensionless parameter $\xi$, which controls the strength of their interaction. While this coupling is commonly assumed to be constant, there is no underlying physical law or…
Interacting dark energy models may play a crucial role in explaining several important observational issues in modern cosmology and also may provide a solution to current cosmological tensions. Since the phenomenology of the dark sector…
The effective theory of isoscalar dark matter-nucleon interactions mediated by heavy spin-one or spin-zero particles depends on 10 coupling constants besides the dark matter particle mass. Here we compare this 11-dimensional effective…
We develop an effective field theory of a generic massive particle of any spin and, as an example, apply this to study higher-spin dark matter (DM). Our formalism does not introduce unphysical degrees of freedom, thus avoiding the potential…
We consider a generic cosmological model which allows for non-gravitational direct couplings between dark matter and dark energy. The distinguishing cosmological features of these couplings can be probed by current cosmological…
We extend the cosmological couplings proposed in Sun et al. and Wei, where they suggested interactions with change of signs along the cosmological evolution. Our extension liberates the changes of sign of the interaction from the…
We formulate an effective field theory (EFT) of coupled dark energy (DE) and dark matter (DM) interacting through energy and momentum transfers. In the DE sector, we exploit the EFT of vector-tensor theories with the presence of a preferred…
We show that an interaction between dark matter and dark energy generically results in an effective dark energy equation of state of w<-1. This arises because the interaction alters the redshift-dependence of the matter density. An observer…
Dark energy and dark matter are the dominant sources in the evolution of the late universe. They are currently only indirectly detected via their gravitational effects, and there could be a coupling between them without violating…
Non-gravitational interaction between dark matter and dark energy has been considered in a spatially flat Friedmann-Lema\^{i}tre-Robertson-Walker (FLRW) universe. The interaction rate is assumed to be linear in the energy densities of dark…
We consider a cosmological model with an interaction between dark matter and dark energy which leaves the background cosmology unaffected and only affects the evolution of the perturbations. This is achieved by introducing a coupling given…