Search Publications
Can past gamma-ray bursts explain both INTEGRAL and ATIC/PAMELA/Fermi anomalies simultaneously?
Kusenko, Alexander; Calvez, Antoine
Gamma-ray bursts (GRBs) have been invoked to explain both the 511 keV emission from the Galactic bulge and the high-energy positron excess inferred from the ATIC, PAMELA, and Fermi data. While independent explanations can be responsible for these phenomena, we explore the possibility of their common GRB-related origin by modeling the GRB distribut…
A theory of dark matter
Arkani-Hamed, Nima; Finkbeiner, Douglas P.; Slatyer, Tracy R. +1 more
We propose a comprehensive theory of dark matter that explains the recent proliferation of unexpected observations in high-energy astrophysics. Cosmic ray spectra from ATIC and PAMELA require a WIMP (weakly interacting massive particle). with mass Mχ∼500 800GeV that annihilates into leptons at a level well above that expected from a the…
New twist on excited dark matter: Implications for INTEGRAL, PAMELA/ATIC/PPB-BETS, DAMA
Cline, James M.; Chen, Fang; Frey, Andrew R.
We show that the 511 keV gamma ray excess observed by INTEGRAL/SPI can be more robustly explained by exciting dark matter (DM) at the center of the galaxy, if there is a peculiar spectrum of DM states χ0, χ1, and χ2, with masses M0∼500GeV, M1≲M0+2me, and M2=M
Figure of merit for dark energy constraints from current observational data
Wang, Yun
In order to make useful comparisons of different dark energy experiments, it is important to choose the appropriate figure of merit (FoM) for dark energy constraints. Here we show that for a set of dark energy parameters {fi}, it is most intuitive to define FoM=1/detCov(f1,f2,f3,…), where Cov(f1
γ-ray polarization constraints on Planck scale violations of special relativity
Ubertini, Pietro; Celotti, Annalisa; Maccione, Luca +2 more
Using recent polarimetric observations of the Crab Nebula in the hard X-ray band by INTEGRAL, we show that the absence of vacuum birefringence effects constrains O(E/M) Lorentz violation in QED to the level |ξ|<9×10-10 at 3σ CL, tightening by more than 3 orders of magnitude previous constraints. We show that planned X-ray polarimeter…
Search for cosmic strings in the Great Observatories Origins Deep Survey
Smoot, G. F.; Christiansen, J. L.; Albin, E. +3 more
We search Hubble Space Telescope Treasury Program images collected as part of the Great Observatories Origins Deep Survey for pairs of galaxies consistent with the gravitational lensing signature of a cosmic string. Our technique includes estimates of the efficiency for finding the lensed galaxy pair. In the north (south) survey field we find no e…
Exciting dark matter and the INTEGRAL/SPI 511keV signal
Finkbeiner, Douglas P.; Weiner, Neal
We propose a dark matter candidate with an “excited state” 1 2 MeV above the ground state, which may be collisionally excited and deexcites by e+e- pair emission. By converting its kinetic energy into pairs, such a particle could produce a substantial fraction of the 511 keV line observed by the International Gamma-Ray Astrop…
MeV right-handed neutrinos and dark matter
Nezri, E.; Frère, J. -M.; Ling, F. -S. +3 more
We consider the possibility of having an MeV right-handed neutrino as a dark matter constituent. The initial reason for this study was the 511 keV spectral line observed by the satellite experiment INTEGRAL: could it be due to an interaction between dark matter and baryons? Independently of this, we find a number of constraints on the assumed righ…
Light neutralino dark matter in the next-to-minimal supersymmetric standard model
Hooper, Dan; Gunion, John F.; McElrath, Bob
Neutralino dark matter is generally assumed to be relatively heavy, with a mass near the electroweak scale. This does not necessarily need to be the case, however. In the next-to-minimal supersymmetric standard model (NMSSM) and other supersymmetric models with an extended Higgs sector, a very light CP-odd Higgs boson can naturally arise making it…
Direct x-ray constraints on sterile neutrino warm dark matter
Beacom, John F.; Watson, Casey R.; Yüksel, Hasan +1 more
Warm dark matter might more easily account for small scale clustering measurements than the heavier particles typically invoked in Λ cold dark matter (ΛCDM) cosmologies. In this paper, we consider a ΛWDM cosmology in which sterile neutrinos νs, with a mass ms of roughly 1 100 keV, are the dark matter. We use the diffuse x-ray…