125 citations · 296 across the 16 of their papers we have counts for
17 papers
Explicit finite-time illustration of improper unitary evolution for the Klein--Gordon field in de Sitter space
William T. Emond, Christian Käding, Peter Millington
It is known that quantum field theories in curved spacetime suffer from a number of pathologies, including the inability to relate states on different spatial slices by proper unit…
Topological modes, non-locality and the double copy
William T. Emond, Laura Engelbrecht, Nathan Moynihan +1
The double copy connects scattering amplitudes and other objects in gauge and gravity theories. Open conceptual issues include whether non-local information in gravity theories can…
Mini-twistors and the Cotton Double Copy
Mariana Carrillo González, William T. Emond, Nathan Moynihan +2
The double copy relates quantities in gauge, gravity and related theories. A well-known procedure for relating exact classical solutions is the Weyl double copy in four spacetime d…
Shrouded black holes in Einstein-Gauss-Bonnet gravity
Eugeny Babichev, William T. Emond, Sabir Ramazanov
We study black holes in a modified gravity scenario involving a scalar field quadratically coupled to the Gauss-Bonnet invariant. The scalar is assumed to be in a spontaneously bro…
Scattering Amplitudes and The Cotton Double Copy
William T. Emond, Nathan Moynihan
We construct classical curvature spinors in topologically massive gauge theory and topologically massive gravity, expressed in terms of massive three-particle amplitudes. We show t…
Quadratic curvature corrections to stringy effective actions and the absence of de Sitter vacua
Francesc Cunillera, William T. Emond, Antoine Lehébel +1
We investigate the combined effect of fluxes and higher-order curvature corrections, in the form of the Gauss-Bonnet term, on the existence of de Sitter vacua in a heterotic string…
Quantization Conditions and the Double Copy
William T. Emond, Nathan Moynihan, Liangyu Wei
We formulate Wilson loop observables as products of eikonal Wilson lines given in terms of on-shell scattering amplitudes. Using these, we derive the Dirac-Schwinger-Zwanziger quan…
Gravitational waves from melting cosmic strings
William T. Emond, Sabir Ramazanov, Rome Samanta
Appearance of cosmic strings in the early Universe is a common manifestation of new physics typically linked to some high energy scale. In this paper, we discuss a different situat…
Anyons and the Double Copy
Daniel J Burger, William T. Emond, Nathan Moynihan
We examine the double copy structure of anyons in gauge theory and gravity. Using on-shell amplitude techniques, we construct little group covariant spinor-helicity variables descr…
Amplitudes from Coulomb to Kerr-Taub-NUT
William T. Emond, Yu-tin Huang, Uri Kol +2
Electric-magnetic duality, the Newman-Janis shift, and the double copy all act by elementary operations on three-point amplitudes. At the same time, they generate a network of inte…
A larger value for by an evolving gravitational constant
Matteo Braglia, Mario Ballardini, William T. Emond +4
We provide further evidence that a massless cosmological scalar field with a non-minimal coupling to the Ricci curvature of the type alleviates…
Black holes in self-tuning cubic Horndeski cosmology
William T. Emond, Antoine Lehébel, Paul M. Saffin
Observations of neutron star mergers in the late Universe have given significant restrictions to the class of viable scalar-tensor theories. In this paper we construct black holes…
Rotating Black Holes in Cubic Gravity
Daniel J. Burger, William T. Emond, Nathan Moynihan
Using on-shell amplitude methods, we derive a rotating black hole solution in a generic theory of Einstein gravity with additional terms cubic in the Riemann tensor. We give an exp…
Scattering Amplitudes, Black Holes and Leading Singularities in Cubic Theories of Gravity
William T Emond, Nathan Moynihan
We compute the semi-classical potential arising from a generic theory of cubic gravity, a higher derivative theory of spin-2 particles, in the framework of modern amplitude techniq…
Well-Tempered Cosmology
William T. Emond, Chunhao Li, Paul M. Saffin +1
We examine an approach to cosmology, known as Well-Tempering, that allows for a de Sitter phase whose expansion is independent of the cosmological constant. Starting from a generic…
Boltzmann equations for preheating
William T. Emond, Peter Millington, Paul M. Saffin
We derive quantum Boltzmann equations for preheating by means of the density matrix formalism, which account for both the non-adiabatic particle production and the leading collisio…
Disformally self-tuning gravity
William T. Emond, Paul M. Saffin
We extend a previous self-tuning analysis of the most general scalar-tensor theory of gravity in four dimensions with second order field equations by considering a generalized coup…