Outputs (6)

Dark energy loopholes some time after GW170817 (2020)
Journal Article
Bordin, L., Copeland, E. J., & Padilla, A. (2020). Dark energy loopholes some time after GW170817. Journal of Cosmology and Astroparticle Physics, 2020(11), Article 063. https://doi.org/10.1088/1475-7516/2020/11/063

We revisit the constraints on scalar tensor theories of modified gravity following the purge of GW170817. We pay particular attention to dynamical loopholes where the anomalous speed of propagation of the gravitational wave can vanish on-shell, when... Read More about Dark energy loopholes some time after GW170817.

Constraints on primordial gravitational waves from the cosmic microwave background (2020)
Journal Article
Clarke, T. J., Copeland, E. J., & Moss, A. (2020). Constraints on primordial gravitational waves from the cosmic microwave background. Journal of Cosmology and Astroparticle Physics, 2020(10), Article 002. https://doi.org/10.1088/1475-7516/2020/10/002

Searches for primordial gravitational waves have resulted in constraints in a large frequency range from a variety of sources. The standard Cosmic Microwave Background (CMB) technique is to parameterise the tensor power spectrum in terms of the tenso... Read More about Constraints on primordial gravitational waves from the cosmic microwave background.

Classical decay rates of oscillons (2020)
Journal Article
Zhang, H.-Y., Amin, M. A., Copeland, E. J., Saffin, P. M., & Lozanov, K. D. (2020). Classical decay rates of oscillons. Journal of Cosmology and Astroparticle Physics, 2020(07), 055-055. https://doi.org/10.1088/1475-7516/2020/07/055

Oscillons are extremely long-lived, spatially-localized field configurations in real-valued scalar field theories that slowly lose energy via radiation of scalar waves. Before their eventual demise, oscillons can pass through (one or more) exceptiona... Read More about Classical decay rates of oscillons.

Shift-symmetric orbital inflation: Single field or multifield? (2020)
Journal Article
Achúcarro, A., Copeland, E. J., Iarygina, O., Palma, G. A., Wang, D.-G., & Welling, Y. (2020). Shift-symmetric orbital inflation: Single field or multifield?. Physical Review D, 102(2), Article 021302(R). https://doi.org/10.1103/physrevd.102.021302

We present a new class of two-field inflationary attractor models, known as shift-symmetric orbital inflation, whose behavior is strongly multifield but whose predictions are remarkably close to those of single-field inflation. In these models, the f... Read More about Shift-symmetric orbital inflation: Single field or multifield?.

Constraints on the cosmic string loop collapse fraction from primordial black holes (2020)
Journal Article
James-Turner, C., Weil, D. P. B., Green, A. M., & Copeland, E. J. (2020). Constraints on the cosmic string loop collapse fraction from primordial black holes. Physical Review D, 101(12), Article 123526. https://doi.org/10.1103/physrevd.101.123526

A small fraction, f , of cosmic string loops can collapse to form Primordial Black Holes (PBHs). Constraints on the abundance of PBHs can therefore be used to constrain f. We update these calculations, taking into account the PBH extended mass functi... Read More about Constraints on the cosmic string loop collapse fraction from primordial black holes.

Understanding the suppression of structure formation from dark matter-dark energy momentum coupling (2020)
Journal Article
Chamings, F. N., Avgoustidis, A., Copeland, E. J., Green, A. M., & Pourtsidou, A. (2020). Understanding the suppression of structure formation from dark matter-dark energy momentum coupling. Physical Review D, 101(4), https://doi.org/10.1103/physrevd.101.043531

Models in which scalar field dark energy interacts with dark matter via a pure momentum coupling have previously been found to potentially ease the structure formation tension between early-and late-universe observations. In this article we explore t... Read More about Understanding the suppression of structure formation from dark matter-dark energy momentum coupling.