Search Publications
Relic neutrinos, thermal axions, and cosmology in early 2014
Di Valentino, Eleonora; Melchiorri, Alessandro; Mena, Olga +2 more
We present up-to-date cosmological bounds on the sum of active neutrino masses as well as on extended cosmological scenarios with additional thermal relics, as thermal axions or sterile neutrino species. Our analyses consider all the current available cosmological data in the beginning of year 2014, including the very recent and most precise baryo…
Variable gravity: A suitable framework for quintessential inflation
Saridakis, Emmanuel N.; Myrzakulov, R.; Hossain, Md. Wali +1 more
In this paper, we investigate a scenario of variable gravity and apply it to the unified description of inflation and late-time cosmic acceleration dubbed quintessential inflation. The scalar field called "cosmon," which in this model unifies both the concepts, reduces to the inflaton at early epochs. We calculate the slow-roll parameters, the Hub…
Constraints on modified Newtonian dynamics theories from radio tracking data of the Cassini spacecraft
Jacobson, R. A.; Folkner, W. M.; Hees, A. +1 more
The modified Newtonian dynamics (MOND) is an attempt to modify the gravitation theory to solve the dark matter problem. This phenomenology is very successful at the galactic level. The main effect produced by MOND in the Solar System is called the external field effect parametrized by the parameter Q2. We have used nine years of Cassini…
Observational constraints on slow-roll inflation coupled to a Gauss-Bonnet term
Koh, Seoktae; Lee, Bum-Hoon; Lee, Wonwoo +1 more
We study slow-roll inflation with a Gauss-Bonnet term that is coupled to an inflaton field nonminimally. We investigate the inflationary solutions for a specific type of the nonminimal coupling to the Gauss-Bonnet term and inflaton potential both analytically and numerically. We also calculate the observable quantities such as the power spectra of…
Detection of warm and diffuse baryons in large scale structure from the cross correlation of gravitational lensing and the thermal Sunyaev-Zeldovich effect
Van Waerbeke, Ludovic; Hinshaw, Gary; Murray, Norman
We report the first detection of a correlation between gravitational lensing by large scale structure and the thermal Sunyaev-Zeldovich (tSZ) effect. Using the mass map from the Canada France Hawaii Telescope Lensing Survey and a newly constructed tSZ map from Planck, we measure a nonzero correlation between the two maps out to one degree angular …
Multifield inflation after Planck: Isocurvature modes from nonminimal couplings
Schutz, Katelin; Sfakianakis, Evangelos I.; Kaiser, David I.
Recent measurements by the Planck experiment of the power spectrum of temperature anisotropies in the cosmic microwave background radiation reveal a deficit of power in low multipoles compared to the predictions from best-fit ΛCDM cosmology. If the low-ℓ anomaly persists after additional observations and analysis, it might be explained by the pres…
Exploring the full parameter space for an interacting dark energy model with recent observations including redshift-space distortions: Application of the parametrized post-Friedmann approach
Zhang, Jing-Fei; Zhang, Xin; Li, Yun-He
Dark energy can modify the dynamics of dark matter if there exists a direct interaction between them. Thus, a measurement of the structure growth, e.g., redshift-space distortions (RSDs), can provide a powerful tool to constrain the interacting dark energy (IDE) models. For the widely studied Q =3 β H ρde model, previous works showed th…
Chasing the phantom: A closer look at type Ia supernovae and the dark energy equation of state
Shafer, Daniel L.; Huterer, Dragan
Some recent observations provide >2σ evidence for phantom dark energy—a value of the dark energy equation of state less than the cosmological-constant value of -1. We focus on constraining the equation of state by combining current data from the most mature geometrical probes of dark energy: type Ia supernovae (SNe Ia) from the Supernova Legacy…
Searching for oscillations in the primordial power spectrum. II. Constraints from Planck data
Spergel, David N.; Meerburg, P. Daniel; Wandelt, Benjamin D.
In this second of two papers we apply our recently developed code to search for resonance features in the Planck CMB temperature data. We search both for log-spaced oscillations or linear-spaced oscillations and compare our findings with results of our WMAP9 analysis and the Planck team analysis [P. A. R. Ade et al. (Planck Collaboration>), arX…
Combining Planck data with large scale structure information gives a strong neutrino mass constraint
Riemer-Sørensen, Signe; Davis, Tamara M.; Parkinson, David
We present the strongest current cosmological upper limit on the neutrino mass of ∑mν<0.18 eV (95% confidence). It is obtained by adding observations of the large-scale matter power spectrum from the WiggleZ Dark Energy Survey to observations of the cosmic microwave background data from the Planck surveyor, and measurements of the ba…