147 citations · 1.1k across the 30 of their papers we have counts for
30 papers
The phenomenology of Axion Relic Pockets
Wafaa Khater, M. C. David Marsh, Charalampos Nikolis
Axion relic pockets are phase-transition remnants consisting of regions of false vacuum stabilised from collapse by a hot axion gas. Axion relic pockets can comprise dark matter, b…
Investigating the gamma-ray burst from decaying MeV-scale axion-like particles produced in supernova explosions
Eike Müller, Francesca Calore, Pierluca Carenza +2
We investigate the characteristics of the gamma-ray signal following the decay of MeV-scale Axion-Like Particles (ALPs) coupled to photons which are produced in a Supernova (SN) ex…
Non-Gaussianity in rapid-turn multi-field inflation
Oksana Iarygina, M. C. David Marsh, Gustavo Salinas
We show that theories of inflation with multiple, rapidly turning fields can generate large amounts of non-Gaussianity. We consider a general theory with two fields, an arbitrary f…
On the applicability of the Landau-Zener formula to axion-photon conversion
Pierluca Carenza, M. C. David Marsh
Axions and photons resonantly interconvert in regions where the plasma frequency approximately equals the axion mass. This process is directly analogous to an avoided level crossin…
Transient Radio Lines from Axion Miniclusters and Axion Stars
Samuel J. Witte, Sebastian Baum, Matthew Lawson +3
Gravitationally bound clumps of dark matter axions in the form of 'miniclusters' or even denser 'axion stars' can generate strong radio signals through axion-photon conversion when…
Physics Beyond the Standard Model with Future X-ray Observatories: Projected Constraints on Very-Light Axion-Like Particles with and
Júlia Sisk-Reynés, Christopher S. Reynolds, Michael L. Parker +2
Axion-Like Particles (ALPs) are well-motivated extensions of the Standard Model of Particle Physics and a generic prediction of some string theories. X-ray observations of bright A…
Magnetohydrodynamics predicts heavy-tailed distributions of axion-photon conversion
Pierluca Carenza, Ramkishor Sharma, M. C. David Marsh +2
The interconversion of axionlike particles (ALPs) and photons in magnetised astrophysical environments provides a promising route to search for ALPs. The strongest limits to date o…
Strong supernovae bounds on ALPs from quantum loops
Ricardo Z. Ferreira, M. C. David Marsh, Eike Müller
We show that in theories of axionlike particles (ALPs) coupled to electrons at tree-level, the one-loop effective coupling to photons is process dependent: the effective coupling r…
Do direct detection experiments constrain axionlike particles coupled to electrons?
Ricardo Z. Ferreira, M. C. David Marsh, Eike Müller
Several laboratory experiments have published limits on axionlike particles (ALPs) with feeble couplings to electrons and masses in the keV-MeV range, under the assumption that suc…
New constraints on light Axion-Like Particles using Chandra Transmission Grating Spectroscopy of the powerful cluster-hosted quasar H1821+643
Júlia Sisk Reynés, James H. Matthews, Christopher S. Reynolds +3
Axion-Like Particles (ALPs) are predicted by several Beyond the Standard Model theories, in particular, string theory. In the presence of an external magnetic field perpendicular t…
The Fourier formalism for relativistic axion-photon conversion, with astrophysical applications
M. C. David Marsh, James H. Matthews, Christopher Reynolds +1
We study the weak mixing of photons and relativistic axion-like particles (axions) in plasmas with background magnetic fields, . We show that, to leading order in the axio…
Axion-photon conversion in strongly magnetised plasmas
Alexander J. Millar, Sebastian Baum, Matthew Lawson +1
Axion dark matter can resonantly convert to photons in the magnetosphere of neutron stars, possibly giving rise to radio signals observable on Earth. This method for the indirect d…
Local, algebraic simplifications of Gaussian random fields
Theodor Bjorkmo, M. C. David Marsh
Many applications of Gaussian random fields and Gaussian random processes are limited by the computational complexity of evaluating the probability density function, which involves…
Manyfield Inflation in Random Potentials
Theodor Bjorkmo, M. C. David Marsh
We construct models of inflation with many randomly interacting fields and use these to study the generation of cosmological observables. We model the potentials as multi-dimension…
Seven Lessons from Manyfield Inflation in Random Potentials
Mafalda Dias, Jonathan Frazer, M. C. David Marsh
We study inflation in models with many interacting fields subject to randomly generated scalar potentials. We use methods from non-equilibrium random matrix theory to construct the…
A New Bound on Axion-Like Particles
M. C. David Marsh, Helen R. Russell, Andrew C. Fabian +3
Axion-like particles (ALPs) and photons can quantum mechanically interconvert when propagating through magnetic fields, and ALP-photon conversion may induce oscillatory features in…
Dimensional Reduction for D3-brane Moduli
Brad Cownden, Andrew R. Frey, M. C. David Marsh +1
Warped string compactifications are central to many attempts to stabilize moduli and connect string theory with cosmology and particle phenomenology. We present a first-principles…
Exacerbating the cosmological constant problem with interacting dark energy
M. C. David Marsh
Future cosmological surveys will probe the expansion history of the universe and constrain phenomenological models of dark energy. Such models do not address the fine-tuning proble…
Simple emergent power spectra from complex inflationary physics
Mafalda Dias, Jonathan Frazer, M. C. David Marsh
We construct ensembles of random scalar potentials for interacting scalar fields using non-equilibrium random matrix theory, and use these to study the generation of observab…
Universal Properties of Type IIB and F-theory Flux Compactifications at Large Complex Structure
M. C. David Marsh, Kepa Sousa
We consider flux compactifications of type IIB string theory and F-theory in which the respective superpotentials at large complex structure are dominated by cubic or quartic terms…
The Spectra of Type IIB Flux Compactifications at Large Complex Structure
Callum Brodie, M. C. David Marsh
We compute the spectra of the Hessian matrix, , and the matrix that governs the critical point equation of the low-energy effective supergravity, as a function…
Galaxy Cluster Thermal X-Ray Spectra Constrain Axion-Like Particles
Joseph P. Conlon, M. C. David Marsh, Andrew J. Powell
Axion-like particles (ALPs) and photons inter-convert in the presence of a magnetic field. At keV energies in the environment of galaxy clusters, the conversion probability can bec…
Decoupling and de Sitter Vacua in Approximate No-Scale Supergravities
M. C. David Marsh, Bert Vercnocke, Timm Wrase
We study supergravity with chiral superfields in which one of the fields has a Kähler potential of exact no-scale type. Such systems admit de Sitter (dS) solutio…
Observational consistency and future predictions for a 3.5 keV ALP to photon line
Pedro D. Alvarez, Joseph P. Conlon, Francesca V. Day +2
Motivated by the possibility of explaining the 3.5 keV line through dark matter decaying to axion-like particles that subsequently convert to photons, we study ALP-photon conversio…