Search Publications
Leveraging SN Ia spectroscopic similarity to improve the measurement of H 0
Filippenko, Alexei V.; Jones, David O.; Riess, Adam G. +7 more
Recent studies suggest spectroscopic differences explain a fraction of the variation in Type Ia supernova (SN Ia) luminosities after light-curve/color standardization. In this work, (i) we empirically characterize the variations of standardized SN Ia luminosities, and (ii) we use a spectroscopically inferred parameter, SIP, to improve the precisio…
Putting all the X in one basket: Updated X-ray constraints on sub-GeV Dark Matter
Pinetti, Elena; Fornengo, Nicolao; Cirelli, Marco +2 more
Sub-GeV dark matter particles can annihilate or decay producing e ± pairs which upscatter the low-energy photon fields in the Galaxy and generate an X-ray emission (via the Inverse Compton effect). Using X-ray data from XMM-NEWTON, INTEGRAL, NUSTAR and SUZAKU, we derive new constraints on this class of dark matter (DM). In the annihilat…
Constraining cosmology with the Gaia-unWISE Quasar Catalog and CMB lensing: structure growth
Hogg, David W.; Rix, Hans-Walter; Eilers, Anna-Christina +4 more
We study the angular clustering of Quaia, a Gaia- and unWISE-based catalog of over a million quasars with an exceptionally well-defined selection function. With it, we derive cosmology constraints from the amplitude and growth of structure across cosmic time. We divide the sample into two redshift bins, centered at z = 1.0 and z = 2.1, and measure…
Stepped partially acoustic dark matter: likelihood analysis and cosmological tensions
Marques-Tavares, Gustavo; Buen-Abad, Manuel A.; Chacko, Zackaria +2 more
We generalize the recently proposed Stepped Partially Acoustic Dark Matter (SPartAcous) model by including additional massless degrees of freedom in the dark radiation sector. We fit SPartAcous and its generalization against cosmological precision data from the cosmic microwave background, baryon acoustic oscillations, large-scale structure, super…
Updated constraints on primordial black hole evaporation
Korwar, Mrunal; Profumo, Stefano
The Hawking evaporation process, leading to the production of detectable particle species, constrains the abundance of light black holes, presumably of primordial origin. Here, we reconsider and correct constraints from soft gamma-ray observations, including of the gamma-ray line, at 511 keV, produced by electron-positron pair-annihilation, where …
Detecting dark compact objects in Gaia DR4: A data analysis pipeline for transient astrometric lensing searches
Kongsore, Marius; Chen, I. -Kai; Tilburg, Ken Van
The Gaia satellite is cataloging the astrometric properties of an unprecedented number of stars in the Milky Way with extraordinary precision. This provides a gateway for conducting extensive surveys of transient astrometric lensing events caused by dark compact objects. In this work, we establish a data analysis pipeline capable of searching for …
Exploring the effects of primordial non-Gaussianity at galactic scales
Famaey, Benoit; Ibata, Rodrigo; Stahl, Clément +2 more
While large scale primordial non-Gaussianity is strongly constrained by present-day data, there are no such constraints at Mpc scales. Here we investigate the effect of significant small-scale primordial non-Gaussianity on structure formation and the galaxy formation process with collisionless simulations: specifically, we explore four different t…
Astrometric microlensing of primordial black holes with Gaia
Rentala, Vikram; Verma, Himanshu
The Gaia space telescope allows for unprecedented accuracy for astrometric measurements of stars in the Galaxy. In this work, we explore the sensitivity of Gaia to detect primordial black hole (PBH) dark matter through the distortions that PBHs would create in the apparent trajectories of background stars, an effect known as astrometric microlensi…
A' view of the sunrise: boosting helioscopes with angular information
Frerick, Jonas; Kahlhoefer, Felix; Schmidt-Hoberg, Kai
The Sun may copiously produce hypothetical light particles such as axions or dark photons, a scenario which can be experimentally probed with so-called helioscopes. Here we investigate the impact of the angular and spectral distribution of solar dark photons on the sensitivity of such instruments. For the first time we evaluate this spectral and a…
The morphology of exciting dark matter and the galactic 511 keV signal
Vincent, Aaron C.; Cappiello, Christopher V.; Jafs, Michael
We study the morphology of the 511 keV signal that could be produced by exciting dark matter (XDM) in the Milky Way. In this model, collisions between dark matter particles excite the dark matter to a state that can then decay back to the ground state, releasing an electron-positron pair. These electrons and positrons would then annihilate, produc…