Search Publications
Effect of aberration on partial-sky measurements of the cosmic microwave background temperature power spectrum
Wang, Xin; Jeong, Donghui; Kamionkowski, Marc +2 more
Our motion relative to the cosmic microwave background (CMB) rest frame deflects light rays giving rise to shifts as large as ℓ→ℓ(1±β), where β =0.00123 is our velocity (in units of the speed of light) on measurements of CMB fluctuations. Here we present a novel harmonic-space approach to this CMB aberration that improves upon prior work by allowi…
Modified gravity with massive neutrinos as a testable alternative cosmological model
Baugh, Carlton M.; Barreira, Alexandre; Li, Baojiu +1 more
We show that, in the presence of massive neutrinos, the Galileon gravity model provides a very good fit to the current cosmic microwave background (CMB) temperature, CMB lensing and baryonic acoustic oscillation data. This model, which we dub νGalileon, when assuming its stable attractor background solution, contains the same set of free parameter…
Dark side of the Universe after Planck data
Cheng, Cheng; Huang, Qing-Guo
Recently released Planck data imply a smaller Hubble constant H0 than that from the Hubble Space Telescope project (HST) and a larger percentage of the matter components Ωm compared to the Supernova Legacy Survey (SNLS) in the Λ cold dark matter (CDM) model. In this paper we found that even though the tension on H0…
Constraining topological defects with temperature and polarization anisotropies
Kunz, Martin; Liddle, Andrew R.; Lizarraga, Joanes +3 more
We analyze the possible contribution of topological defects to cosmic microwave anisotropies, both temperature and polarization. We allow for the presence of both inflationary scalars and tensors, and of polarized dust foregrounds that may contribute to or dominate the B-mode polarization signal. We confirm and quantify our previous statements tha…
Inflationary freedom and cosmological neutrino constraints
de Putter, Roland; Linder, Eric V.; Mishra, Abhilash
The most stringent bounds on the absolute neutrino mass scale come from cosmological data. These bounds are made possible because massive relic neutrinos affect the expansion history of the universe and lead to a suppression of matter clustering on scales smaller than the associated free streaming length. However, the resulting effect on cosmologi…
Single field inflation with modulated potential in light of Planck and BICEP2
Wan, Youping; Li, Siyu; Li, Mingzhe +3 more
The recently released BICEP2 data detected the primordial B-mode polarization in the cosmic microwave background (CMB) map which strongly supports for a large tensor-to-scalar ratio, and, thus, is found to be in tension with the Planck experiment with no evidence of primordial gravitational waves. Such an observational tension, if confirmed by for…
Effects of long-lived 10 MeV-scale sterile neutrinos on primordial elemental abundances and the effective neutrino number
Ishida, Hiroyuki; Kusakabe, Motohiko; Okada, Hiroshi
The primordial lithium abundance inferred from spectroscopic observations of metal-poor stars is ∼3 times smaller than the theoretical prediction in the standard big bang nucleosynthesis (BBN) model. We assume a simple model composed of standard model particles and a sterile neutrino νH with mass of O(10) MeV which decays long afte…
Mapping the integrated Sachs-Wolfe effect
Dodelson, S.; Manzotti, A.
On large scales, the anisotropies in the cosmic microwave background (CMB) reflect not only the primordial density field but also the energy gain when photons traverse decaying gravitational potentials of large scale structure, what is called the integrated Sachs-Wolfe (ISW) effect. Decomposing the anisotropy signal into a primordial piece and an …
Alleviating the tension at low ℓ through axion monodromy
Meerburg, P. Daniel
There exists some tension on large scales between the Planck data and the ΛCDM concordance model of the Universe, which has been amplified by the recently claimed discovery of nonzero tensor-to-scalar ratio r. At the same time, the current best-fit value of r suggests large field inflation Δϕinf>Mp, which requires a U…
Constraints on a decomposed dark fluid with constant adiabatic sound speed by jointing the geometry test and growth rate after Planck data
Yang, Weiqiang; Xu, Lixin; Wang, Yuting +1 more
In this paper, a unified dark fluid with constant adiabatic sound speed is decomposed into cold dark matter interacting with vacuum energy. Based on a Markov-chain Monte Carlo method, we constrain this model by jointing the geometry and dynamical measurement. The geometry test includes cosmic microwave background radiation from Planck, baryon acou…