Search Publications
The Atacama Cosmology Telescope: Sunyaev-Zel'dovich selected galaxy clusters at 148 GHz from three seasons of data
Hilton, Matt; Hasselfield, Matthew; Sifón, Cristóbal +41 more
We present a catalog of 68 galaxy clusters, of which 19 are new discoveries, detected via the Sunyaev-Zel'dovich effect (SZ) at 148 GHz in the Atacama Cosmology Telescope (ACT) survey on the celestial equator. With this addition, the ACT collaboration has reported a total of 91 optically confirmed, SZ detected clusters. The 504 square degree surve…
A lower bound on the mass of cold thermal dark matter from Planck
Dolan, Matthew J.; Bœhm, Céline; McCabe, Christopher
We show that the new measurement of the effective number of neutrinos (Neff) by the Planck satellite can be used to set a robust lower bound on the mass of cold thermal dark matter of Script O(MeV). Our limit applies if the dark matter remains in thermal equilibrium by coupling to electrons and photons or through interactions with neutr…
A new life for sterile neutrinos: resolving inconsistencies using hot dark matter
Hamann, Jan; Hasenkamp, Jasper
Within the standard ΛCDM model of cosmology, the recent Planck measurements have shown discrepancies with other observations, e.g., measurements of the current expansion rate H0, the galaxy shear power spectrum and counts of galaxy clusters. We show that if ΛCDM is extended by a hot dark matter component, which could be interpreted as a…
Planck constraints on holographic dark energy
Zhang, Xin; Li, Miao; Ma, Yin-Zhe +2 more
We perform a detailed investigation on the cosmological constraints on the holographic dark energy (HDE) model by using the Plank data. We find that HDE can provide a good fit to the Plank high-l (l gtrsim 40) temperature power spectrum, while the discrepancy at l simeq 20-40 found in the ΛCDM model remains unsolved in the HDE model. The Plank dat…
Cosmology with massive neutrinos III: the halo mass function and an application to galaxy clusters
Viel, Matteo; Xia, Jun-Qing; Costanzi, Matteo +4 more
We use a suite of N-body simulations that incorporate massive neutrinos as an extra-set of particles to investigate their effect on the halo mass function. We show that for cosmologies with massive neutrinos the mass function of dark matter haloes selected using the spherical overdensity (SO) criterion is well reproduced by the fitting formula of …
Axion hot dark matter bounds after Planck
Mirizzi, Alessandro; Archidiacono, Maria; Hannestad, Steen +2 more
We use cosmological observations in the post-Planck era to derive limits on thermally produced cosmological axions. In the early universe such axions contribute to the radiation density and later to the hot dark matter fraction. We find an upper limit ma < 0.67 eV at 95% C.L. after marginalising over the unknown neutrino masses, usin…
Low & high scale MSSM inflation, gravitational waves and constraints from Planck
Choudhury, Sayantan; Mazumdar, Anupam; Pal, Supratik
In this paper we will analyze generic predictions of an inflection-point model of inflation with Hubble-induced corrections and study them in light of the Planck data. Typically inflection-point models of inflation can be embedded within Minimal Supersymmetric Standard Model (MSSM) where inflation can occur below the Planck scale. The flexibility …
Observational signatures of anisotropic inflationary models
Ohashi, Junko; Tsujikawa, Shinji; Soda, Jiro
We study observational signatures of two classes of anisotropic inflationary models in which an inflaton field couples to (i) a vector kinetic term FµνFµν and (ii) a two-form kinetic term HµνλHµνλ. We compute the corrections from the anisotropic sources to the power spectrum of gr…
The effect of dark matter and dark energy interactions on the peculiar velocity field and the kinetic Sunyaev-Zel'dovich effect
Wang, Bin; Xu, Xiao-Dong; Zhang, Pengjie +1 more
The interaction between Dark Matter and Dark Energy has been proposed as a mechanism to alleviate the coincidence problem. We analyze its effects on the evolution of the gravitational and the peculiar velocity fields. We find that for different model parameters peculiar velocities vary from a factor five times smaller to two times larger than in t…
Dark radiation sterile neutrino candidates after Planck data
Di Valentino, Eleonora; Melchiorri, Alessandro; Mena, Olga
Recent Cosmic Microwave Background (CMB) results from the Planck satellite, combined with previous CMB data and Hubble constant measurements from the Hubble Space Telescope, provide a constraint on the effective number of relativistic degrees of freedom 3.62+0.50-0.48 at 95% CL. New Planck data provide a unique opportunity to…