Search Publications
Dark Matter Equation of State through Cosmic History
Kopp, Michael; Skordis, Constantinos; Thomas, Daniel B. +1 more
Cold dark matter is a crucial constituent of the current concordance cosmological model. Having a vanishing equation of state (EOS), its energy density scales with the inverse cosmic volume and is thus uniquely described by a single number, its present abundance. We test the inverse cosmic volume law for dark matter (DM) by allowing its EOS to var…
No Evidence for Extensions to the Standard Cosmological Model
Sellentin, Elena; Heavens, Alan; Hosenie, Zafiirah +4 more
We compute the Bayesian evidence for models considered in the main analysis of Planck cosmic microwave background data. By utilizing carefully defined nearest-neighbor distances in parameter space, we reuse the Monte Carlo Markov chains already produced for parameter inference to compute Bayes factors B for many different model-data set combinatio…
From Planck Data to Planck Era: Observational Tests of Holographic Cosmology
Afshordi, Niayesh; Corianò, Claudio; Delle Rose, Luigi +2 more
We test a class of holographic models for the very early Universe against cosmological observations and find that they are competitive to the standard cold dark matter model with a cosmological constant (Λ CDM ) of cosmology. These models are based on three-dimensional perturbative superrenormalizable quantum field theory (QFT), and, while they pr…
Measurement of a Cosmographic Distance Ratio with Galaxy and Cosmic Microwave Background Lensing
Madhavacheril, Mathew S.; Miyatake, Hironao; Spergel, David N. +4 more
We measure the gravitational lensing shear signal around dark matter halos hosting constant mass galaxies using light sources at z ∼1 (background galaxies) and at the surface of last scattering at z ∼1100 (the cosmic microwave background). The galaxy shear measurement uses data from the CFHTLenS survey, and the microwave background shear measureme…
Improved Constraints on Cosmology and Foregrounds from BICEP2 and Keck Array Cosmic Microwave Background Data with Inclusion of 95 GHz Band
Ade, P. A. R.; Bock, J. J.; Crill, B. P. +59 more
We present results from an analysis of all data taken by the BICEP2 and Keck Array cosmic microwave background (CMB) polarization experiments up to and including the 2014 observing season. This includes the first Keck Array observations at 95 GHz. The maps reach a depth of 50 nK deg in Stokes Q and U in the 150 GHz band and 127 nK deg in the 95 GH…
Kinematic Sunyaev-Zel'dovich Effect with Projected Fields: A Novel Probe of the Baryon Distribution with Planck, WMAP, and WISE Data
Spergel, David N.; Ferraro, Simone; Hill, J. Colin +2 more
The kinematic Sunyaev-Zel'dovich (KSZ) effect—the Doppler boosting of cosmic microwave background (CMB) photons due to Compton scattering off free electrons with nonzero bulk velocity—probes the abundance and the distribution of baryons in the Universe. All KSZ measurements to date have explicitly required spectroscopic redshifts. Here, we impleme…
How Isotropic is the Universe?
Peiris, Hiranya V.; Feeney, Stephen M.; Pontzen, Andrew +2 more
A fundamental assumption in the standard model of cosmology is that the Universe is isotropic on large scales. Breaking this assumption leads to a set of solutions to Einstein's field equations, known as Bianchi cosmologies, only a subset of which have ever been tested against data. For the first time, we consider all degrees of freedom in these s…
Demonstration of Cosmic Microwave Background Delensing Using the Cosmic Infrared Background
Sherwin, Blake D.; Challinor, Anthony; Larsen, Patricia +1 more
Delensing is an increasingly important technique to reverse the gravitational lensing of the cosmic microwave background (CMB) and thus reveal primordial signals the lensing may obscure. We present a first demonstration of delensing on Planck temperature maps using the cosmic infrared background (CIB). Reversing the lensing deflections in Planck C…
Joint Analysis of BICEP2/Keck Array and Planck Data
Kneissl, R.; Miville-Deschênes, M. -A.; Boulanger, F. +277 more
We report the results of a joint analysis of data from BICEP2/Keck Array and Planck. BICEP2 and Keck Array have observed the same approximately 400 deg2 patch of sky centered on RA 0 h, Dec. -57.5 ° . The combined maps reach a depth of 57 nK deg in Stokes Q and U in a band centered at 150 GHz. Planck has observed the full sky in polariz…
Observing Inflationary Reheating
Ringeval, Christophe; Martin, Jérôme; Vennin, Vincent
Reheating is the epoch which connects inflation to the subsequent hot big-bang phase. Conceptually very important, this era is, however, observationally poorly known. We show that the current Planck satellite measurements of the cosmic microwave background (CMB) anisotropies constrain the kinematic properties of the reheating era for most of the i…