782 citations · 6.7k across the 109 of their papers we have counts for
115 papers
A Simple Dark Matter Model to Explain the LZ Event and Galactic Center Excess
Caleb Gemmell, Dan Hooper, Gordan Krnjaic
We propose that the dark matter (DM) is a pseudo-Dirac fermion with a mass of approximately GeV that couples inelastically to the Standard Model through a hadrophilic spin…
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…
Getting Warmer: IceCube Nears Freeze Out
Mainak Mukhopadhyay, Gordan Krnjaic
IceCube has recently detected a diffuse population of high-energy neutrinos arising from the Milky Way. We use this high-significance detection to place new limits on dark matter (…
Baryogenesis via the CKM Matrix with Minimal Flavor Violation
Innes Bigaran, Gordan Krnjaic, Kevin Langhoff +1
It is often claimed Standard Model CP violation is insufficient for baryogenesis. We present a counterexample using minimal flavor violation (MFV) in which all CP-violating effects…
Probing the Cosmic Axion Background via Axion-Photon Conversion in Filaments
Duncan Rocha, Gordan Krnjaic, Matthew J. Baldwin
The cosmic axion background (CaB) is a hypothetical population of relativistic axions produced in the early universe. If the CaB is produced from dark matter decays, the axions in…
Expected Sensitivity of the Light Dark Matter eXperiment to Long-Lived Dark Photons and Axion-Like Particles
Torsten Akesson, Clay Barton, Charles Bell +53
The Light Dark Matter eXperiment (LDMX) is an electron-beam fixed-target experiment primarily designed to achieve world-leading, model-independent sensitivity to sub-GeV dark matte…
WIMP-like Dark Matter Without Thermalization At Freeze-Out
Dan Hooper, Gordan Krnjaic, Gabriele Montefalcone
In the standard thermal relic scenario, dark matter remains in chemical equilibrium with the Standard Model radiation bath until freeze-out occurs at , where i…
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…
New Thermal-Relic Targets for sub-GeV Dark Matter Direct Detection
Xu Han, Gordan Krnjaic
Dark matter direct detection experiments involving electron recoils are beginning to test highly-predictive, thermal-relic milestones for sub-GeV dark matter models. Due to the Lee…
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…
A Thermal Relic Encyclopedia: Dark Matter Candidates Coupled to Quarks
Dan Hooper, Gordan Krnjaic, Tanner Trickle +1
Thermal freeze-out is a compelling framework for naturally generating the dark matter abundance. We systematically study a broad range of dark matter and mediator particle combinat…
LDMX -- The Light Dark Matter eXperiment
Torsten Akesson, Layan Alsaraya, Stephen Appert +116
The Light Dark Matter eXperiment (LDMX) is an electron fixed-target experiment optimized to search for sub-GeV dark matter production through the missing momentum signature. LDMX i…
X-rays from Inelastic Dark Matter Freeze-in
Gordan Krnjaic, David McKeen, Riku Mizuta +3
We study inelastic dark matter produced via freeze-in through a light mediator with a mass splitting below the electron-positron threshold. In this regime, the heavier dark matter…
Sensitivity of an Early Dark Matter Search using the Electromagnetic Calorimeter as a Target for the Light Dark Matter eXperiment
LDMX Collaboration, Torsten Åkesson, Elizabeth Berzin +53
The Light Dark Matter eXperiment (LDMX) is proposed to employ a thin tungsten target and a multi-GeV electron beam to carry out a missing momentum search for the production of dark…
Gamma-Rays and Gravitational Waves from Inelastic Higgs Portal Dark Matter
Dan Hooper, Gordan Krnjaic, Duncan Rocha +1
We explore a simple and predictive dark matter scenario involving a complex scalar field, , coupled to the Higgs portal with no additional field content. In the UV, the field po…
Testing Thermal-Relic Dark Matter with a Dark Photon Mediator
Gordan Krnjaic
In light of recent DAMIC-M results, we present the status of thermal-relic dark matter coupled to a kinetically-mixed dark photon . In the predictive "direct annihila…
dSphobic Dark Matter
Asher Berlin, Joshua W. Foster, Dan Hooper +1
We present a mechanism that allows thermal relic dark matter to annihilate efficiently in the Galactic Halo and in galaxy clusters, but not in the lower-velocity environments of dw…
Observing Dark Matter Decays to Gravitons via Graviton-Photon Conversion
David I. Dunsky, Gordan Krnjaic, Elena Pinetti
Since dark matter is only known to have gravitational interactions, it may plausibly decay to gravitons on cosmological timescales. Although such a scenario can be easily realized,…
Direct Detection of Ultralight Dark Matter via Charged Lepton Flavor Violation
Innes Bigaran, Patrick J. Fox, Yann Gouttenoire +4
We propose a dark matter direct-detection strategy using charged particle decays at accelerator-based experiments. If ultralight dark matter has a misalignment…
Testing the Froggatt-Nielsen Mechanism with Lepton Flavor and Number Violating Processes
Claudia Cornella, David Curtin, Gordan Krnjaic +1
The Froggatt-Nielsen (FN) mechanism offers an elegant explanation for the observed masses and mixings of Standard Model fermions. In this work, we systematically study FN models in…
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…
The Affleck-Dine Curvaton
Aurora Ireland, Gordan Krnjaic, Takuya Okawa
The Standard Model of particle physics does not explain the origin of the universe's baryon asymmetry or its primordial fluctuations. The Affleck-Dine mechanism is a well-motivated…