Search Publications
Constraints on Lorentz Invariance Violation using integral/IBIS observations of GRB041219A
Covino, S.; Götz, D.; Laurent, P. +2 more
One of the experimental tests of Lorentz invariance violation is to measure the helicity dependence of the propagation velocity of photons originating in distant cosmological obejcts. Using a recent determination of the distance of the gamma-ray burst GRB 041219A, for which a high degree of polarization is observed in the prompt emission, we are a…
Metastable dark matter mechanisms for INTEGRAL 511 keV γ rays and DAMA/CoGeNT events
Cline, James M.; Chen, Fang; Frey, Andrew R.
We explore dark matter mechanisms that can simultaneously explain the galactic 511 keV gamma rays observed by INTEGRAL/SPI, the DAMA/LIBRA annual modulation, and the excess of low-recoil dark matter candidates observed by CoGeNT. It requires three nearly degenerate states of dark matter in the 4-7 GeV mass range, with splittings, respectively, of …
Search for cosmic strings in the COSMOS survey
Smoot, G. F.; Christiansen, J. L.; Albin, E. +4 more
We search the COSMOS survey for pairs of galaxies consistent with the gravitational lensing signature of a cosmic string. The COSMOS survey imaged 1.64 square degrees using the Advanced Camera for Surveys aboard the Hubble Space Telescope. Our technique includes estimates of the efficiency for finding the lensed galaxy pair. We find no evidence fo…
Real space CMB lensing reconstruction with point source masks
Carvalho, C. Sofia; Tereno, Ismael
An incomplete sky coverage poses difficulties in the extraction of the weak lensing information from the CMB. We test the reconstruction of the weak lensing convergence from CMB maps to which masks of point sources have been applied. We use the quadratic estimator with a kernel with finite support acting in real space for a Planck simulation. We r…