Related papers: Challenges for $\Lambda$CDM: An update
We use updated Hubble parameter and baryon acoustic oscillation data, as well as other lower-redshift Type Ia supernova, Mg II reverberation-measured quasar, quasar angular size, H II starburst galaxy, and Amati-correlated gamma-ray burst…
Observational constraints are considered on a $w_{log}$CDM model of the dark energy equation of state, $w_{d}(z) = w_{0} + w_{a}\left( \frac{\ln(2+z)}{1+z} - \ln 2 \right)$, using the most recent cosmological datasets including DESI Baryon…
The increasing precision of Cosmic Microwave Background (CMB) observations has unveiled significant tensions between different datasets, notably between Planck and the Atacama Cosmology Telescope (ACT), as well as with the late-Universe…
Tensions between cosmological measurements by different surveys or probes have always been important --- and are presently much discussed --- as they may lead to evidence of new physics. Several tests have been devised to probe the…
For a flat $\Lambda$CDM (standard) cosmology, a small sample of gravitationally lensed quasars with measured time delays has recently provided a value of the Hubble constant $H_0$ in tension with the $Planck$ flat $\Lambda$CDM result.…
The current standard model of cosmology - the {\ensuremath{\Lambda}}CDM model - is appropriately named after its controversial foreign ingredients: a cosmological constant ({\ensuremath{\Lambda}}) that accounts for the recent accelerated…
Measurements of the Hubble constant, and more generally measurements of the expansion rate and distances over the interval $0 < z < 1$, appear to be inconsistent with the predictions of the standard cosmological model ($\Lambda$CDM) given…
We present a comprehensive analysis of statistical tools for evaluating tensions in cosmological parameter estimates arising from distinct datasets. Focusing on the unresolved Hubble constant ($H_0$) tension, we explore the Pantheon Plus +…
A simple and natural extension of the standard Lambda cold dark matter ($\Lambda$CDM) model is to allow relic neutrinos to have finite chemical potentials. We confront this $\Lambda$CDM$\xi$ model, a $\Lambda$CDM with neutrino mass $M_\nu$…
Several cosmological tensions have emerged in light of recent data, most notably in the inferences of the parameters $H_0$ and $\sigma_8$. We explore the possibility of alleviating both these tensions {\it simultaneously} by means of the…
In this talk I will review the current status of the constraints on the neutrino properties from cosmological measurements, with a particular focus on their mass and effective number. I will also discuss the existing tensions within the…
Taking the Planck cosmic microwave background data and the more direct Hubble constant measurement data as unaffected by systematic offsets, the values of the Hubble constant $H_0$ interpreted within the $\Lambda$CDM cosmological constant…
Recently, a low-$z$ measurement of the Hubble constant, $H_0 = 73.04 \pm 1.04 {\rm ~km/s/Mpc}$, was reported by the SH0ES Team. The long-standing Hubble tension, i.e. the difference between the Hubble constant from the local measurements…
In the last years with the increasing precision in cosmological observations we have been able to establish a standard model of cosmology, the so-called $\Lambda$CDM, but also find some tensions between cosmological probes that are…
Future precision measurements of CMB polarizations can shed new light on the problem so called Hubble tension. The Hubble tension comes from the difference of the evolutions of the Hubble parameter which are determined with two different…
In this work, we carry out a comprehensive perturbative analysis of four cosmological models featuring a sign-switching cosmological constant. Among these, we include the well-known $\Lambda_{\rm s}$CDM model, characterised by an abrupt…
This paper is based on two insights: (1) that general relativity alone does not specify how much of the matter density contributes to the source term in Friedmann's equation, and how much contributes as the source of the gravitational…
In this work, we investigate a cosmological scenario with a time-dependent cosmological constant $\Lambda$(t) within the spatially flat Friedmann-Lema\^itre-Robertson-Walker (FLRW) framework. Here we study a power-law $\Lambda(t)$CDM model…
The tension between current expansion rate H$_0$ using Planck data and direct model-independent measurements in the local universe has reached a tension above 5$\sigma$ in the context of the $\Lambda$CDM model. The growing tension among…
This paper introduces a novel cosmological model aimed at probing the accelerated expansion of the late Universe through a unique parametrization of the deceleration parameter. We aim to constrain key cosmic parameters by integrating recent…