Search Publications
Post-Planck constraints on interacting vacuum energy
Zhao, Gong-Bo; Xu, Lixin; Wang, Yuting +1 more
We present improved constraints on an interacting vacuum model using updated astronomical observations including the first data release from Planck. We consider a model with one dimensionless parameter, α, describing the interaction between dark matter and vacuum energy (with fixed equation of state w=-1). The background dynamics correspond to a g…
Constraining supersymmetry using the relic density and the Higgs boson
Rauch, Michael; Plaszczynski, Stéphane; Henrot-Versillé, Sophie +5 more
Recent measurements by Planck, LHC experiments, and Xenon100 have significant impact on supersymmetric models and their parameters. We first illustrate the constraints in the mSUGRA plane and then perform a detailed analysis of the general minimal supersymmetric Standard Model (MSSM) with 13 free parameters. Using SFitter, Bayesian and profile lik…
Information gains from cosmic microwave background experiments
Amara, Adam; Refregier, Alexandre; Seehars, Sebastian +2 more
To shed light on the fundamental problems posed by dark energy and dark matter, a large number of experiments have been performed and combined to constrain cosmological models. We propose a novel way of quantifying the information gained by updates on the parameter constraints from a series of experiments which can either complement earlier measur…
Inflationary steps in the Planck data
Hu, Wayne; Miranda, Vinícius
We extend and improve the modeling and analysis of large-amplitude, sharp inflationary steps for second order corrections required by the precision of the Planck cosmic microwave background power spectrum and for arbitrary Dirac-Born-Infeld sound speed. With two parameters, the amplitude and frequency of the resulting oscillations, step models imp…
Cosmic equation of state from combined angular diameter distances: Does the tension with luminosity distances exist?
Cao, Shuo; Zhu, Zong-Hong
Using relatively complete observational data concerning four angular diameter distance (ADD) measurements and combined SN +GRB observations representing current luminosity distance (LD) data, this paper investigates the compatibility of these two cosmological distances considering three classes of dark energy equation of state (EoS) reconstruction…
Reconstruction of the primordial power spectra with Planck and BICEP2 data
Hu, Bin; Cai, Rong-Gen; Guo, Zong-Kuan +1 more
By using the cubic spline interpolation method, we reconstruct the shape of the primordial scalar and tensor power spectra from the recently released Planck temperature and BICEP2 polarization cosmic microwave background data. We find that the vanishing scalar index running (dns/dlnk) model is strongly disfavored at more than 3σ confide…
Probing nuclear rates with Planck and BICEP2
Di Valentino, Eleonora; Melchiorri, Alessandro; Lesgourgues, Julien +4 more
Big-bang nucleosynthesis (BBN) relates key cosmological parameters to the primordial abundance of light elements. In this paper, we point out that the recent observations of cosmic microwave background anisotropies by the Planck satellite and by the BICEP2 experiment constrain these parameters with such a high level of accuracy that the primordial…
Primordial tensor modes from quantum corrected inflation
Joergensen, Jakob; Sannino, Francesco; Svendsen, Ole
We analyze quantum corrections on the naive ϕ4 inflation. These typically lead to an inflaton potential which carries a noninteger power of the field. We consider both minimal and nonminimal couplings to gravity. For the latter case we also study unitarity of inflaton-inflaton scattering. Finally we confront these theories with the Plan…
Directional dependence of CMB parity asymmetry
Zhao, Wen
Parity violation in the cosmic microwave background (CMB) radiation has been confirmed by recent Planck observation. In this paper, we extend our previous work [P. Naselsky et al., Astrophys. J. 749, 31 (2012)] on the directional properties of CMB parity asymmetry by considering the Planck data of the CMB temperature anisotropy. We define six kind…
Estimating the contribution of Galactic sources to the diffuse neutrino flux
Anchordoqui, Luis A.; Goldberg, Haim; Paul, Thomas C. +2 more
Motivated by recent IceCube observations we reexamine the idea that microquasars are high energy neutrino emitters. By stretching to the maximum the parameters of the Fermi engine we show that the nearby high-mass x-ray binary LS 5039 could accelerate protons up to above about 20 PeV. These highly relativistic protons could subsequently interact w…