Related papers: Do Observations Prefer Thawing Quintessence?
An alternative dark energy description based on a generalized K-essence scenario is here explored. In particular, we consider a \emph{quasi-quintessence} and/or \emph{quasi-phantom} field, whose pressure does not depend on the kinetic…
The DESI Collaboration reports a significant preference for a dynamic dark energy model ($w_0w_a$CDM) over the cosmological constant ($\Lambda$CDM) when their data are combined with other frontier cosmological probes. We present a direct…
The latest results on baryon acoustic oscillations from DESI (Dark Energy Spectroscopic Instrument), when combined with cosmic microwave background and supernova data, show indications of a deviation from a cosmological constant in favour…
The two most popular candidates for dark energy, i.e. a cosmological constant and quintessence, are very difficult to distinguish observationally, mostly because the quintessence field does not have sizable fluctuations. We study a scalar…
Recent results from the Dark Energy Spectroscopic Instrument (DESI) have shown a strong statistical preference for a time-evolving dark energy model over $\Lambda$CDM when combining BAO, CMB, and supernova (SN) data. We investigate the…
We present a general parametrization for energy density of a quintessence field, a minimally coupled canonical scalar field which rolls down slowly during the late time. This parametrization can mimic all classes of quintessence dynamics,…
We use linear perturbation theory to study perturbations in dynamical dark energy models. We compare quintessence and tachyonic dark energy models with identical background evolution. We write the corresponding equations for different…
Recent measurements of Baryon Acoustic Oscillations (BAO) and distance moduli from Type Ia supernovae suggest a preference for Dynamical Dark Energy (DDE) scenarios characterized by a time-varying equation of state (EoS). This focused…
Cosmic microwave background data from the {\it Planck} satellite, combined with baryon acoustic oscillation measurements from the Dark Energy Spectroscopic Instrument and Type Ia supernovae from various samples, provide hints of dynamical…
We do a detailed analysis of a well-theoretically motivated interacting dark energy scalar field model with a time-varying interaction term. Using current cosmological datasets from CMB, BAO, Type Ia Supernova, $H(z)$ measurements from…
Recent observations of DESI hint that dark matter (DM) may not be cold but have a non-zero equation of state (EoS) parameter, and that dark energy (DE) may not be a cosmological constant. In this work, we explore the possibility of a…
The late time acceleration of the Universe can be characterized in terms of an extra, time dependent, component of the universe -- dark energy. The simplest proposal for dark energy is a scalar-tensor theory -- quintessence -- which…
We implement Crossing Statistics to reconstruct in a model-agnostic manner the expansion history of the universe and properties of dark energy, using DESI Data Release 1 (DR1) BAO data in combination with one of three different supernova…
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…
In this paper, we investigate a quintessence field with an exponential potential motivated by the suggestion of time-varying dark energy from the DESI galaxy survey. Assuming a kination epoch in the early Universe, we analytically derive…
We investigate potential deviations from cold dark matter (CDM) using the latest Baryon Acoustic Oscillations (BAO) measurements from the Dark Energy Spectroscopic Instrument (DESI). Analyzing DESI data alone constrains the dark matter…
We analyse pre-DESI clustering data using a dark energy equation of state $w(z)$ parametrised by $(w_0, w_a)$, finding a $2.8-3.9\sigma$ preference for evolving dark energy over the cosmological constant $\Lambda$ when combined with cosmic…
We use a dynamical systems approach to study thawing quintessence models, using a multi-parameter extension of the exponential potential which can approximate the form of typical thawing potentials. We impose observational constraints using…
This work delves into the dynamical dark energy models of the wCDM parameterisation that are defined by their equation of state by comparing different, well-known parameterisation models, in an attempt to lessen the tensions of {H_0} and…
One fundamental physics interpretation of Dark Energy Spectroscopic Instrument (DESI) results is that the observed accelerated expansion of the Universe is driven not by the cosmological constant, but by a slowly rolling scalar field, a…