717 citations · 4.8k across the 112 of their papers we have counts for
6 papers · 1 filter
Deep Learning the Morphology of Dark Matter Substructure
Stephon Alexander, Sergei Gleyzer, Evan McDonough +2
Strong gravitational lensing is a promising probe of the substructure of dark matter halos. Deep learning methods have the potential to accurately identify images containing substr…
Higher Spin Supersymmetry at the Cosmological Collider: Sculpting SUSY Rilles in the CMB
Stephon Alexander, S. James Gates, Leah Jenks +2
We study the imprint of higher spin supermultiplets on cosmological correlators, namely the non-Gaussianity of the cosmic microwave background. Supersymmetry is used as a guide to…
The cosmology of minimal varying Lambda theories
Stephon Alexander, Marina Cortês, Andrew R. Liddle +3
Inserting a varying Lambda in Einstein's field equations can be made consistent with the Bianchi identities by allowing for torsion, without the need to add scalar field degrees of…
A Zero-Parameter Extension of General Relativity with Varying Cosmological Constant
Stephon Alexander, Marina Cortês, Andrew R. Liddle +3
We provide a new extension of general relativity (GR) which has the remarkable property of being more constrained than GR plus a cosmological constant, having one less free paramet…
Axion-Dilaton Destabilization and the Hubble Tension
Stephon Alexander, Evan McDonough
The discrepancy in measurements of the Hubble constant indicates new physics in dark energy, dark matter, or both. Drawing inspiration from string theory, where axions interact wit…
Dark Disk Substructure and Superfluid Dark Matter
Stephon Alexander, Jason J. Bramburger, Evan McDonough
Dark matter substructure has the potential to discriminate between broad classes of dark matter models. With this in mind, we construct novel solutions to the equations of motion g…