RESUMEN
BINGO (BAO from Integrated Neutral Gas Observations) is a unique radio telescope designed to map the intensity of neutral hydrogen distribution at cosmological distances, making the first detection of Baryon Acoustic Oscillations (BAO) in the frequency band 980 MHz - 1260 MHz, corresponding to a redshift range 0.127 < z < 0.449. BAO is one of the most powerful probes of cosmological parameters and BINGO was designed to detect the BAO signal to a level that makes it possible to put new constraints on the equation of state of dark energy. The telescope will be built in Paraíba, Brazil and consists of two \thicksim 40m mirrors, a feedhorn array of 50 horns, and no moving parts, working as a drift-scan instrument. It will cover a 15 ^{\circ} ∘ declination strip centered at \sim \delta ⼠δ =-15 ^{\circ} ∘ , mapping \sim â¼ 5400 square degrees in the sky. The BINGO consortium is led by University of São Paulo with co-leadership at National Institute for Space Research and Campina Grande Federal University (Brazil). Telescope subsystems have already been fabricated and tested, and the dish and structure fabrication are expected to start in late 2020, as well as the road and terrain preparation.
RESUMEN
We investigate the impact of prior models on the upper bound of the sum of neutrino masses, ∑m_{ν}. Using data from the large scale structure of galaxies, cosmic microwave background, type Ia supernovae, and big bang nucleosynthesis, we argue that cosmological neutrino mass and hierarchy determination should be pursued using exact models, since approximations might lead to incorrect and nonphysical bounds. We compare constraints from physically motivated neutrino mass models (i.e., ones respecting oscillation experiments) to those from models using standard cosmological approximations. The former give a consistent upper bound of ∑m_{ν}â²0.26 eV (95% CI) and yield the first approximation-independent upper bound for the lightest neutrino mass species, m_{0}^{ν}<0.086 eV (95% CI). By contrast, one of the approximations, which is inconsistent with the known lower bounds from oscillation experiments, yields an upper bound of ∑m_{ν}â²0.15 eV (95% CI); this differs substantially from the physically motivated upper bound.
RESUMEN
We observe a large excess of power in the statistical clustering of luminous red galaxies in the photometric SDSS galaxy sample called MegaZ DR7. This is seen over the lowest multipoles in the angular power spectra C_{â} in four equally spaced redshift bins between 0.45≤z≤0.65. However, it is most prominent in the highest redshift band at â¼4σ and it emerges at an effective scale kâ²0.01 h Mpc(-1). Given that MegaZ DR7 is the largest cosmic volume galaxy survey to date (3.3(Gpch(-1))(3)) this implies an anomaly on the largest physical scales probed by galaxies. Alternatively, this signature could be a consequence of it appearing at the most systematically susceptible redshift. There are several explanations for this excess power that range from systematics to new physics. We test the survey, data, and excess power, as well as possible origins.
RESUMEN
We present a new limit of ∑m(v) ≤ 0.28 (95% CL) on the sum of the neutrino masses assuming a flat ΛCDM cosmology. This relaxes slightly to ∑m(ν) ≤ 0.34 and ∑m(v) ≤ 0.47 when quasinonlinear scales are removed and w≠ -1, respectively. These are derived from a new photometric catalogue of over 700,000 luminous red galaxies (MegaZ DR7) with a volume of 3.3 (Gpc h(-1))(3) and redshift range 0.45 < z < 0.65. The data are combined with WMAP 5-year CMB, baryon acoustic oscillations, supernovae, and a Hubble Space Telescope prior on h. When combined with WMAP these data are as constraining as adding all supernovae and baryon oscillation data available. The upper limit is one of the tightest constraints on the neutrino from cosmology or particle physics. Further, if these bounds hold, they all predict that current-to-next generation neutrino experiments, such as KATRIN, are unlikely to obtain a detection.
