Alleviating the H0 and σ8 anomalies with a decaying dark matter model

  title={Alleviating the H0 and $\sigma$8 anomalies with a decaying dark matter model},
  author={Kanhaiya Pandey and Tanvi Karwal and Subinoy Das},
  journal={arXiv: Cosmology and Nongalactic Astrophysics},
The Hubble tension between the $\Lambda$CDM-model-dependent prediction of the current expansion rate $H_0$ using Planck data and direct, model-independent measurements in the local universe from the SH0ES collaboration disagree at $>3.5\sigma$. Moreover, there exists a milder $\sim 2\sigma$ tension between similar predictions for the amplitude $S_8$ of matter fluctuations and its measurement in the local universe. As explanations relying on unresolved systematics have not been found, theorists… Expand

Figures and Tables from this paper

Interacting scenarios with dynamical dark energy: Observational constraints and alleviation of the H0 tension
We investigate interacting scenarios which belong to a wider class, since they include a dynamical dark energy component whose equation of state follows various one-parameter parametrizations. WeExpand
Cosmology Intertwined II: The Hubble Constant Tension
The current cosmological probes have provided a fantastic confirmation of the standard $\Lambda$ Cold Dark Matter cosmological model, that has been constrained with unprecedented accuracy. However,Expand
H0 tension, swampland conjectures, and the epoch of fading dark matter
Motivated by the swampland dS conjecture, we consider a rolling scalar field as the source of dark energy. Furthermore, the swampland distance conjecture suggests that the rolling field will lead atExpand
Cosmological models, observational data and tension in Hubble constant
We analyze how predictions of cosmological models depend on a choice of described observational data, restrictions on flatness, and how this choice can alleviate the $H_0$ tension. These effects areExpand
Nonminimal dark sector physics and cosmological tensions
We explore whether nonstandard dark sector physics might be required to solve the existing cosmological tensions. The properties we consider in combination are (a) an interaction between the darkExpand
Fractional Dark Matter decay: cosmological imprints and observational constraints
If a fraction $f_{\rm dcdm}$ of the Dark Matter decays into invisible and massless particles (so-called "dark radiation") with the decay rate (or inverse lifetime) $\Gamma_{\rm dcdm}$, such decayExpand
Looking for interactions in the cosmological dark sector
We study observational signatures of non-gravitational interactions between the dark components of the cosmic fluid, which can be either due to creation of dark particles from the expanding vacuum orExpand
The $H_0$ Olympics: A fair ranking of proposed models
Despite the remarkable success of the Λ Cold Dark Matter (ΛCDM) cosmological model, a growing discrepancy has emerged (currently measured at the level of ∼ 4 − 6σ) between the value of the HubbleExpand
Interacting dark energy after the latest Planck, DES, and $H_0$ measurements: an excellent solution to the $H_0$ and cosmic shear tensions.
We examine the most well-studied model featuring non-gravitational interactions between dark matter and dark energy in light of the latest cosmological observations. Our data includes CosmicExpand
Constraints on Decaying Dark Matter with DES-Y1 and external data
We study a class of decaying dark matter models as a possible resolution to the observed discrepancies between early- and late-time probes of the universe. This class of models, dubbed DDM,Expand


Are H 0 and σ 8 Tensions Generic to Present Cosmological Data?
Yes, for a wide range of cosmological models ($\Lambda$CDM, non-interacting $w_z$CDM or models with possible interactions between dark energy and dark matter, in either phantom or non-phantomExpand
Evidence for dark matter interactions in cosmological precision data
We study a two-parameter extension of the cosmological standard model $\Lambda$CDM in which cold dark matter interacts with a new form of dark radiation. The two parameters correspond to the energyExpand
Implications of an extended dark energy cosmology with massive neutrinos for cosmological tensions
We perform a comprehensive analysis of the most common early- and late-Universe solutions to the $H_0$, Ly-$\alpha$, and $S_8$ discrepancies. When considered on their own, massive neutrinos provide aExpand
Interacting Dark Sector and Precision Cosmology
We consider a recently proposed model in which dark matter interacts with a thermal background of dark radiation. Dark radiation consists of relativistic degrees of freedom which allow larger valuesExpand
Constraining dark energy dynamics in extended parameter space
Dynamical dark energy has been recently suggested as a promising and physical way to solve the 3.4 sigma tension on the value of the Hubble constant $H_0$ between the direct measurement of Riess etExpand
Dark matter component decaying after recombination: Lensing constraints with Planck data
It has been recently suggested [Z. Berezhiani, A. D. Dolgov, and I. I. Tkachev, Phys. Rev. D 92, 061303 (2015)] that emerging tension between cosmological parameter values derived in high-redshiftExpand
Decaying dark matter and the tension in σ8
We consider decaying dark matter (DDM) as a resolution to the possible tension between cosmic microwave background (CMB) and weak lensing (WL) based determinations of the amplitude of matterExpand
Cosmological bounds on dark matter-photon coupling
We investigate an extension of the $\Lambda$CDM model where the dark matter (DM) is coupled to photons. In addition, we consider the presence of massive neutrinos with the effective number of speciesExpand
The trouble with $H_0$
We perform a comprehensive cosmological study of the $H_0$ tension between the direct local measurement and the model-dependent value inferred from the Cosmic Microwave Background. With the recentExpand
Beyond six parameters: extending $\Lambda$CDM
Cosmological constraints are usually derived under the assumption of a $6$ parameters $\Lambda$-CDM theoretical framework or simple one-parameter extensions. In this paper we present, for the firstExpand