782 citations · 6.7k across the 109 of their papers we have counts for
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AXIS Could Have Accessed Dark Matter Decays
Joshua W. Foster, Inci Karaaslan, Gordan Krnjaic +1
The Advanced X-ray Imaging Satellite (AXIS) was a mission concept designed to improve upon the sensitivity and spatial resolution of the Chandra X-ray Observatory and XMM-Newton. A…
Primordial Neutron Stars
Gordan Krnjaic, Duncan Rocha, Huangyu Xiao
We propose a novel cosmological scenario in which baryonic neutron stars could plausibly form in the early universe. If baryogenesis initially produces an excessively-large baryon…
A Universal CMB -Mode Spectrum from Early Causal Tensor Sources
Kylar Greene, Aurora Ireland, Gordan Krnjaic +1
Many early universe scenarios predict post-inflationary tensor perturbations from causality-limited, sub-horizon sources. While the microphysical details may differ, as long as the…
First constraints on causal sources of primordial gravitational waves from BICEP/Keck, SPTpol, SPT-3G, Planck and WMAP -mode data
Jessica A. Zebrowski, Aurora Ireland, Christian L. Reichardt +4
Non-inflationary sources of gravitational waves in the early Universe generically predict causality-limited tensor power spectra at low frequencies. We report the first-ever constr…
Clustering and Runaway Merging in a Primordial Black Hole Dominated Universe
Ian Holst, Gordan Krnjaic, Huangyu Xiao
If primordial black holes (PBH) are present in the early universe, their contribution to the energy budget grows relative to that of radiation and generically becomes dominant unle…
Observable CMB B-modes from Cosmological Phase Transitions
Kylar Greene, Aurora Ireland, Gordan Krnjaic +1
A B-mode polarization signal in the cosmic microwave background (CMB) is widely regarded as smoking gun evidence for gravitational waves produced during inflation. Here, we demonst…
Warm Hawking Relics From Primordial Black Hole Domination
Christopher J. Shallue, Julian B. Muñoz, Gordan Z. Krnjaic
We study the cosmological impact of warm, dark-sector relic particles produced as Hawking radiation in a primordial-black-hole-dominated universe before big bang nucleosynthesis. I…
Supermassive Primordial Black Holes From Inflation
Dan Hooper, Aurora Ireland, Gordan Krnjaic +1
There is controversy surrounding the origin and evolution of our universe's largest supermassive black holes (SMBHs). In this study, we consider the possibility that some of these…
Probing The Longest Dark Matter Lifetimes with the Line Emission Mapper
Gordan Krnjaic, Elena Pinetti
In the next decade, the proposed Line Emission Mapper (LEM) telescope concept is poised to revolutionize Galactic and extragalactic X-ray sensitivity. The instruments aboard LEM fe…
Cosmological Magnetic Fields from Primordial Kerr-Newman Black Holes
Dan Hooper, Aurora Ireland, Gordan Krnjaic
The origin of our universe's cosmological magnetic fields remains a mystery. In this study, we consider whether these magnetic fields could have been generated in the early univers…
Investigation of CMB constraints for dark matter-helium scattering
Kimberly K. Boddy, Gordan Krnjaic, Stacie Moltner
We study dark matter-helium scattering in the early Universe and its impact on constraints from cosmic microwave background (CMB) anisotropy measurements. We describe possible theo…
The First Three Seconds: a Review of Possible Expansion Histories of the Early Universe
Rouzbeh Allahverdi, Mustafa A. Amin, Asher Berlin +23
It is commonly assumed that the energy density of the Universe was dominated by radiation between reheating after inflation and the onset of matter domination 54,000 years later. W…
Hot Gravitons and Gravitational Waves From Kerr Black Holes in the Early Universe
Dan Hooper, Gordan Krnjaic, John March-Russell +2
Any abundance of black holes that was present in the early universe will evolve as matter, making up an increasingly large fraction of the total energy density as space expands. Th…
New Limits on Charged Dark Matter from Large-Scale Coherent Magnetic Fields
Albert Stebbins, Gordan Krnjaic
We study the interaction of an electrically charged component of the dark matter with a magnetized galactic interstellar medium (ISM) of (rotating) spiral galaxies. For the observe…
Constraining the Self-Interacting Neutrino Interpretation of the Hubble Tension
Nikita Blinov, Kevin J. Kelly, Gordan Krnjaic +1
Large, non-standard neutrino self-interactions have been shown to resolve the tension in Hubble constant measurements and a milder tension in the amplitude of matter fluc…
Dark Matter Detection with Polarized Detectors
Chi-Ting Chiang, Marc Kamionkowski, Gordan Z. Krnjaic
We consider the prospects to use polarized dark-matter detectors to discriminate between various dark-matter models. If WIMPs are fermions and participate in parity-violating inter…