Search Publications
Large-scale stability and astronomical constraints for coupled dark-energy models
Yang, Weiqiang; Pan, Supriya; Barrow, John D.
We study large-scale inhomogeneous perturbations and instabilities of interacting dark-energy models. Past analysis of large-scale perturbative instabilities has shown that we can only test interacting dark-energy models with observational data when their parameter ranges are either wx≥-1 and ξ ≥0 , or wx≤-1 and ξ ≤0 , where …
Explaining LIGO's observations via isolated binary evolution with natal kicks
Belczynski, Krzysztof; Holz, Daniel E.; Berti, Emanuele +5 more
We compare binary evolution models with different assumptions about black-hole natal kicks to the first gravitational-wave observations performed by the LIGO detectors. Our comparisons attempt to reconcile merger rate, masses, spins, and spin-orbit misalignments of all current observations with state-of-the-art formation scenarios of binary black …
Indirect detection of neutrino portal dark matter
Batell, Brian; Han, Tao; Shams Es Haghi, Barmak
We investigate the feasibility of the indirect detection of dark matter in a simple model using the neutrino portal. The model is very economical, with right-handed neutrinos generating neutrino masses through the type-I seesaw mechanism and simultaneously mediating interactions with dark matter. Given the small neutrino Yukawa couplings expected …
Dark matter hurricane: Measuring the S1 stream with dark matter detectors
Belokurov, Vasily; Evans, N. Wyn; Myeong, GyuChul +2 more
The recently discovered S1 stream passes through the Solar neighborhood on a low inclination, counterrotating orbit. The progenitor of S1 is a dwarf galaxy with a total mass comparable to the present-day Fornax dwarf spheroidal, so the stream is expected to have a significant DM component. We compute the effects of the S1 stream on WIMP and axion …
Updated tomographic analysis of the integrated Sachs-Wolfe effect and implications for dark energy
Bilicki, Maciej; Lesgourgues, Julien; Cuoco, Alessandro +1 more
We derive updated constraints on the integrated Sachs-Wolfe (ISW) effect through cross-correlation of the cosmic microwave background with galaxy surveys. We improve with respect to similar previous analyses in several ways. First, we use the most recent versions of extragalactic object catalogs, SDSS DR12 photometric redshift (photo-z ) and 2MASS…
MICROSCOPE limits for new long-range forces and implications for unified theories
Fayet, Pierre
Many theories beyond the standard model involve an extra U (1 ) gauge group. The resulting gauge boson U , in general mixed with the Z and the photon, may be massless or very light and very weakly coupled. It may be viewed as a generalized dark photon interacting with matter through a linear combination [ɛQQ +ɛBB +ɛL
Do current cosmological observations rule out all covariant Galileons?
Peirone, Simone; Frusciante, Noemi; Hu, Bin +2 more
We revisit the cosmology of covariant Galileon gravity in view of the most recent cosmological data sets, including weak lensing. As a higher derivative theory, covariant Galileon models do not have a Λ CDM limit and predict a very different structure formation pattern compared with the standard Λ CDM scenario. Previous cosmological analyses sugge…
Two-halo term in stacked thermal Sunyaev-Zel'dovich measurements: Implications for self-similarity
Hill, J. Colin; Jain, Bhuvnesh; Greco, Johnny P. +2 more
The relation between the mass and integrated electron pressure of galaxy group and cluster halos can be probed by stacking maps of the thermal Sunyaev-Zel'dovich (tSZ) effect. Perhaps surprisingly, recent observational results have indicated that the scaling relation between integrated pressure and mass follows the prediction of simple, self-simil…
Price of shifting the Hubble constant
Evslin, Jarah; Ruchika; Sen, Anjan A.
An anisotropic measurement of the baryon acoustic oscillation (BAO) feature fixes the product of the Hubble constant and the acoustic scale H0rd. Therefore, regardless of the dark energy dynamics, to accommodate a higher value of H0 one needs a lower rd and so necessarily a modification of early time cos…
Model independent inference of the expansion history and implications for the growth of structure
Joudaki, Shahab; Kirkby, David; Kaplinghat, Manoj +1 more
We model the expansion history of the Universe as a Gaussian process and find constraints on the dark energy density and its low-redshift evolution using distances inferred from the Luminous Red Galaxy and Lyman-alpha data sets of the Baryon Oscillation Spectroscopic Survey, supernova data from the Joint Light-Curve Analysis sample, cosmic microwa…