Search Publications
Cosmic microwave background constraints on primordial black hole dark matter
Blum, Kfir; Flauger, Raphael; Aloni, Daniel
We revisit cosmic microwave background (CMB) constraints on primordial black hole dark matter. Spectral distortion limits from COBE/FIRAS do not impose a relevant constraint. Planck CMB anisotropy power spectra imply that primordial black holes with mBHgtrsim 5 Msolar are disfavored. However, this is susceptible to sizeable u…
Weighing neutrinos in the scenario of vacuum energy interacting with cold dark matter: application of the parameterized post-Friedmann approach
Zhang, Jing-Fei; Zhang, Xin; Li, Yun-He +1 more
We constrain the neutrino mass in the scenario of vacuum energy interacting with cold dark matter by using current cosmological observations. To avoid the large-scale instability problem in interacting dark energy models, we employ the parameterized post-Friedmann (PPF) approach to do the calculation of perturbation evolution, for the Q = βHρ…
Internal delensing of Planck CMB temperature and polarization
Challinor, Anthony; Carron, Julien; Lewis, Antony
We present a first internal delensing of CMB maps, both in temperature and polarization, using the public foreground-cleaned (SMICA) Planck 2015 maps. After forming quadratic estimates of the lensing potential, we use the corresponding displacement field to undo the lensing on the same data. We build differences of the delensed spectra to the orig…
Cosmic viscosity as a remedy for tension between PLANCK and LSS data
Anand, Sampurn; Chaubal, Prakrut; Mazumdar, Arindam +1 more
Measurements of σ8 from large scale structure observations show a discordance with the extrapolated σ8 from Planck CMB parameters using ΛCDM cosmology. Similar discordance is found in the value of H0 and Ωm. In this paper, we show that the presence of viscosity, shear or bulk or combination of both, can …
Cosmic microwave background constraints on secret interactions among sterile neutrinos
Mirizzi, Alessandro; Lattanzi, Massimiliano; Natoli, Paolo +3 more
Secret contact interactions among eV sterile neutrinos, mediated by a massive gauge boson X (with MX ll MW), and characterized by a gauge coupling gX, have been proposed as a mean to reconcile cosmological observations and short-baseline laboratory anomalies. We constrain this scenario using the latest Planck data …
Low mass X-ray binaries in the Inner Galaxy: implications for millisecond pulsars and the GeV excess
Heinke, Craig; Linden, Tim; Haggard, Daryl +1 more
If millisecond pulsars (MSPs) are responsible for the excess gamma-ray emission observed from the region surrounding the Galactic Center, the same region should also contain a large population of low-mass X-ray binaries (LMXBs). In this study, we compile and utilize a sizable catalog of LMXBs observed in the the Milky Way's globular cluster system…
Cold dark matter plus not-so-clumpy dark relics
Mena, Olga; Gariazzo, Stefano; Weniger, Christoph +2 more
Various particle physics models suggest that, besides the (nearly) cold dark matter that accounts for current observations, additional but sub-dominant dark relics might exist. These could be warm, hot, or even contribute as dark radiation. We present here a comprehensive study of two-component dark matter scenarios, where the first component is a…
Cosmic microwave background constraints for global strings and global monopoles
Lizarraga, Joanes; Urrestilla, Jon; Hindmarsh, Mark +1 more
We present the first cosmic microwave background (CMB) power spectra from numerical simulations of the global O(N) linear σ-model, with N=2,3, which have global strings and monopoles as topological defects. In order to compute the CMB power spectra we compute the unequal time correlators (UETCs) of the energy-momentum tensor, showing that they fal…
Do joint CMB and HST data support a scale invariant spectrum?
Benetti, Micol; Graef, Leila L.; Alcaniz, Jailson S.
We combine current measurements of the local expansion rate, H0, and Big Bang Nucleosynthesis (BBN) estimates of helium abundance with the latest cosmic microwave background (CMB) data from the Planck Collaboration to discuss the observational viability of the scale invariant Harrison-Zeldovch-Peebles (HZP) spectrum. We also analyze som…
Constraints on direction-dependent cosmic birefringence from Planck polarization data
Scott, Douglas; Contreras, Dagoberto; Boubel, Paula
Cosmic birefringence is the process that rotates the plane of polarization by an amount, α, as photons propagate through free space. Such an effect arises in parity-violating extensions to the electromagnetic sector, such as the Chern-Simons term common in axion models, quintessence models, or Lorentz-violating extensions to the standard model. Mo…