Related papers: Addressing the Hubble and $S_8$ Tensions with a Ki…
The $\Lambda$CDM model faces significant challenges, including an incomplete understanding of the dark sector and persistent tensions in the Hubble constant and the clustering amplitude. To address these issues, we propose a general…
Astronomical observations suggest that the current standard $\Lambda$-Cold Dark Matter model in modern cosmology has some discrepancies when fitting the data during the whole expansion history of the universe. To solve the Hubble constant…
We explore a mechanism for producing the baryon asymmetry and dark matter in models with multiple hidden sectors that are Standard-Model-like but with varying Higgs mass parameters. If the field responsible for reheating the Standard Model…
We propose that dark energy in the form of a scalar field could effectively couple to dark matter inhomogeneities. Through this coupling energy could be transferred to/from the scalar field, which could possibly enter an accelerated regime.…
Light moduli fields in string compactifications can have interesting implications for particle physics and cosmology. Fifth force bounds impose stringent constraints on the interactions of such moduli with the visible sector. To be…
Values of the Hubble constant between the direct measurements from various independent local observations and that inferred from the cosmic microwave background with the $\Lambda$-cold-dark-matter model are in tension with persistent…
The discrepancy between early-Universe inferences and direct measurements of the Hubble constant, known as the Hubble tension, recently became a pressing subject in high precision cosmology. As a result, a large variety of theoretical…
We investigate a dark sector coupled to the Standard Model (SM) through a kinetically mixed dark photon $U$ associated with a new $U(1)'$ gauge symmetry. Kinetic mixing $\varepsilon$ induces an effective coupling to the electromagnetic…
Many extensions of Standard Model (SM) include a dark sector which can interact with the SM sector via a light mediator. We explore the possibilities to probe such a dark sector by studying the distortion of the CMB spectrum from the…
We examine a cosmological scenario where dark matter is coupled to a variable vacuum energy while baryons and photons are two decoupled components for a spatially flat Friedmann-Robertson-Walker spacetime. We apply the $\chi^{2}$ method to…
Since current challenges faced by $\Lambda$CDM might be hinting at new unravelled physics, here we investigate a plausible cosmological model where a vector field acts as source of dark energy. In particular, we examine whether an…
We show that relaxion, that addresses the hierarchy problem, can account for the observed dark matter (DM) relic density. The setup is similar to the case of axion DM models topped with a dynamical misalignment mechanism. After the…
The main goal of this work is to propose a generalized model of interacting dark energy which allows for the kinetic term of a scalar field to couple to the matter species a priori in the action. We derive the modified field equations, and…
We explore an interacting dark matter (IDM) model that allows for a fraction of dark matter (DM) to undergo velocity-independent scattering with baryons. In this scenario, structure on small scales is suppressed relative to the cold DM…
The environment-dependent dilaton field is a well-motivated candidate for dark energy and naturally arises in the strong coupling limit of string theory. In this article, we present the very first experimental constraints on the parameters…
We consider the evolution of linear perturbations in models with a nonminimal coupling between dark matter and scalar field dark energy. Growth of matter inhomogeneities in two examples of such models proposed in the literature are…
We present exact inhomogeneous and anisotropic cosmological solutions of low-energy string theory containing dilaton and axion fields. The spacetime metric possesses cylindrical symmetry. The solutions describe ever-expanding universes with…
String-inspired axion model is considered to comprehensively solve the problems of modern cosmology, Hubble tension problem, the origin of the stochastic gravitational wave background, and too early formation of supermassive black holes at…
We present a new mechanism for transferring a pre-existing lepton or baryon asymmetry to a dark matter asymmetry that relies on mass mixing which is dynamically induced in the early universe. Such mixing can succeed with only generic scales…
We study the dynamics of the quintom dark energy model using state-of-the-art cosmological observations. The set of equations has been converted into an autonomous system using suitable transformations of the variables. We have discussed…