86 citations · 459 across the 19 of their papers we have counts for
13 papers · 1 filter
Axion-Photon Conversion in 3D Media and Astrophysical Plasmas
J. I. McDonald, B. Garbrecht, P. Millington
With axions now a primary candidate for dark matter, understanding their indirect astrophysical signatures is of paramount importance. Key to this is the production of photons from…
Axion detection with phonon-polaritons revisited
David J. E. Marsh, Jamie I. McDonald, Alexander J. Millar +1
In the presence of a background magnetic field, axion dark matter induces an electric field and can thus excite phonon-polaritons in suitable materials. We revisit the calculation…
Superradiance in Stars: Non-equilibrium approach to damping of fields in stellar media
Francesca Chadha-Day, Björn Garbrecht, Jamie McDonald
Superradiance in black holes is well-understood but a general treatment for superradiance in stars has until now been lacking. This is surprising given the ease with which we can o…
Dark Matter In Extreme Astrophysical Environments
Masha Baryakhtar, Regina Caputo, Djuna Croon +37
Exploring dark matter via observations of extreme astrophysical environments -- defined here as heavy compact objects such as white dwarfs, neutron stars, and black holes, as well…
Scanning the landscape of axion dark matter detectors: applying gradient descent to experimental design
J. I. McDonald
The hunt for dark matter remains one of the principal objectives of modern physics and cosmology. Searches for dark matter in the form of axions are proposed or underway across a r…
Radio Line Properties of Axion Dark Matter Conversion in Neutron Stars
R. A. Battye, B. Garbrecht, J. I. McDonald +1
Axions are well-motivated candidates for dark matter. Recently, much interest has focused on the detection of photons produced by the resonant conversion of axion dark matter in ne…
Bending of light in axion backgrounds
Jamie I. McDonald, Luís B. Ventura
In this work we examine refraction of light by computing full solutions to axion electrodynamics. We also allow for the possibility of an additional plasma component. We then speci…
Dynamical Evolution of Gravitational Leptogenesis
Jamie I. McDonald, Graham M. Shore
Radiatively-induced gravitational leptogenesis is a potential mechanism to explain the observed matter-antimatter asymmetry of the universe. Gravitational tidal effects at the quan…
Optical properties of dynamical axion backgrounds
Jamie I. McDonald, Luís B. Ventura
We discuss spectral distortions, time delays and refraction of light in an axion or axion-plasma background. This involves solving the full set of geodesic equations associated to…
Axion superradiance in rotating neutron stars
Francesca V. Day, Jamie I. McDonald
It is a well-known fact that compact gravitating objects admit bound state configurations for massive bosonic fields. In this work we describe a new class of superradiant instabili…
Leptogenesis and gravity: baryon asymmetry without decays
J. I. McDonald, G. M. Shore
A popular class of theories attributes the matter-antimatter asymmetry of the Universe to CP-violating decays of super-heavy BSM particles in the Early Universe. Recently, we disco…
Leptogenesis from loop effects in curved spacetime
Jamie I. McDonald, Graham M. Shore
We describe a new mechanism - radiatively-induced gravitational leptogenesis - for generating the matter-antimatter asymmetry of the Universe. We show how quantum loop effects in C…
Radiatively-induced gravitational leptogenesis
J. I. McDonald, G. M. Shore
We demonstrate how loop effects in gravitational backgrounds lead to a difference in the propagation of matter and antimatter, and show this is forbidden in flat space due to CPT a…