Search Publications
Cosmological constraints from DES Y1 cluster abundances and SPT multiwavelength data
Bacon, D.; Smith, M.; Abbott, T. M. C. +89 more
We perform a joint analysis of the counts of redMaPPer clusters selected from the Dark Energy Survey (DES) year 1 data and multiwavelength follow-up data collected within the 2500 deg2 South Pole Telescope (SPT) Sunyaev-Zel'dovich (SZ) survey. The SPT follow-up data, calibrating the richness-mass relation of the optically selected redMa…
Hubble tension or a transition of the Cepheid SnIa calibrator parameters?
Perivolaropoulos, Leandros; Skara, Foteini
We reanalyze the Cepheid data used to infer the value of the Hubble constant H0 by calibrating type Ia supernovae. We do not enforce a universal value of the empirical Cepheid calibration parameters RW (Cepheid Wesenheit color-luminosity parameter) and MHW (Cepheid Wesenheit H-band absolute magnitude). I…
Comparing early dark energy and extra radiation solutions to the Hubble tension with BBN
Seto, Osamu; Toda, Yo
A shorter sound horizon scale at the recombination epoch, arising from introducing extra energy components such as extra radiation or early dark energy (EDE), is a simple approach to resolving the so-called Hubble tension. We compare EDE models, an extra radiation model, and a model in which EDE and extra radiation coexist, paying attention to the…
Dark matter properties through cosmic history
Kopp, Michael; Skordis, Constantinos; Thomas, Daniel B. +1 more
We perform the first test of dark matter (DM) stress-energy evolution through cosmic history, using cosmic microwave background measurements supplemented with baryon acoustic oscillation data and the Hubble Space Telescope key project data. We constrain the DM equation of state (EoS) in 8 redshift bins, and its sound speed and (shear) viscosity in…
Late-time acceleration due to a generic modification of gravity and the Hubble tension
Gangopadhyay, Mayukh R.; Sami, M.; Sharma, Mohit K. +1 more
We consider a scenario of modified gravity, which is generic to late-time acceleration, namely, acceleration in the Jordan frame and no acceleration in the Einstein frame. The possibility is realized by assuming an interaction between dark matter and the baryonic component in the Einstein frame which is removed by going to the Jordan frame using a…
Nonparametric reconstruction of interaction in the cosmic dark sector
Mukherjee, Purba; Banerjee, Narayan
The possibility of a nongravitational interaction between dark matter and dark energy is reconstructed using some recent data sets. The crucial aspect is that the interaction is not parametrized at the outset, but rather reconstructed directly from the data in a nonparametric way. The cosmic chronometer Hubble data, the Pantheon supernova compilat…
Sum of the masses of the Milky Way and M31: A likelihood-free inference approach
Lahav, Ofer; Hoffman, Yehuda; Whiteway, Lorne +3 more
We use density estimation likelihood-free inference, Λ cold dark matter simulations of ∼2 M galaxy pairs, and data from Gaia and the Hubble Space Telescope to infer the sum of the masses of the Milky Way and Andromeda (M31) galaxies, the two main components of the local group. This method overcomes most of the approximations of the traditional tim…
Do the observational data favor a local void?
Cai, Rong-Gen; Guo, Zong-Kuan; Ding, Jia-Feng +2 more
The increasing tension between the different local direct measurements of the Hubble expansion rate and that inferred from the cosmic microwave background observation by the Λ -cold-dark-matter model could be a smoking gun of new physics, if not caused by either observational systematics or local bias. We generalize previous investigation on the l…
Cosmological constraints on Hořava gravity revised in light of GW170817 and GRB170817A and the degeneracy with massive neutrinos
Frusciante, Noemi; Benetti, Micol
We revise the cosmological bounds on Hořava gravity, taking into account the stringent constraint on the speed of propagation of gravitational waves from GW170817 and GRB170817A. In light of this, we also investigate the degeneracy between massive neutrinos and Hořava gravity. We show that a luminal propagation of gravitational waves suppresses th…
Assessing the potential of cluster edges as a standard ruler on constraining dark energy models
Wang, Deng
We assess comprehensively the potential of galaxy cluster edges as a standard ruler in measuring cosmological distances and probing exotic physics. Confronting five alternative cosmological models with cluster edges from the near-future Dark Energy Spectroscopic Instrument survey, we conclude that cluster edges can serve as a promising probe to co…