Outputs (40)

Beyond the growth rate of cosmic structure: Testing modified gravity models with an extra degree of freedom (2017)
Journal Article
Burrage, C., Parkinson, D., & Seery, D. (2017). Beyond the growth rate of cosmic structure: Testing modified gravity models with an extra degree of freedom. Physical Review D, 96(4), Article 043509. https://doi.org/10.1103/PhysRevD.96.043509

© 2017 American Physical Society. In "modified" gravity the observed acceleration of the universe is explained by changing the gravitational force law or the number of degrees of freedom in the gravitational sector. Both possibilities can be tested b... Read More about Beyond the growth rate of cosmic structure: Testing modified gravity models with an extra degree of freedom.

Radial acceleration relation from symmetron fifth forces (2017)
Journal Article
Burrage, C., Copeland, E. J., & Millington, P. (2017). Radial acceleration relation from symmetron fifth forces. Physical Review D, D95(6), Article 064050. https://doi.org/10.1103/PhysRevD.95.064050

We show that the radial acceleration relation for rotationally supported galaxies may be explained, in the absence of cold dark matter, by a nonminimally coupled scalar field, whose fifth forces are partially screened on galactic scales by the symmet... Read More about Radial acceleration relation from symmetron fifth forces.

Constraining symmetron fields with atom interferometry (2016)
Journal Article
Burrage, C., Kuribayashi-Coleman, A., Stevenson, J., & Thrussell, B. (2016). Constraining symmetron fields with atom interferometry. Journal of Cosmology and Astroparticle Physics, 2016, Article 041. https://doi.org/10.1088/1475-7516/2016/12/041

We apply the new constraints from atom-interferometry searches for screening mechanisms to the symmetron model, finding that these experiments exclude a previously unexplored region of the parameter space. We discuss the possibility of networks of do... Read More about Constraining symmetron fields with atom interferometry.

A compendium of chameleon constraints (2016)
Journal Article
Burrage, C., & Sakstein, J. (2016). A compendium of chameleon constraints. Journal of Cosmology and Astroparticle Physics, 2016(11), Article 045. https://doi.org/10.1088/1475-7516/2016/11/045

The chameleon model is a scalar field theory with a screening mechanism that explains how a cosmologically relevant light scalar can avoid the constraints of intra-solar-system searches for fifth-forces. The chameleon is a popular dark energy candida... Read More about A compendium of chameleon constraints.

Radiative screening of fifth forces (2016)
Journal Article
Burrage, C., Copeland, E. J., & Millington, P. (2016). Radiative screening of fifth forces. Physical Review Letters, 117(21), Article 211102. https://doi.org/10.1103/PhysRevLett.117.211102

© 2016 American Physical Society. We describe a symmetron model in which the screening of fifth forces arises at the one-loop level through the Coleman-Weinberg mechanism of spontaneous symmetry breaking. We show that such a theory can avoid current... Read More about Radiative screening of fifth forces.

LHC signatures of scalar dark energy (2016)
Journal Article
Burrage, C., Brax, P., Englert, C., & Spannowsky, M. (2016). LHC signatures of scalar dark energy. Physical Review D - Particles, Fields, Gravitation and Cosmology, 94, Article 084054. https://doi.org/10.1103/PhysRevD.94.084054

Scalar dark energy fields that couple to the standard model can give rise to observable signatures at the LHC. In this work, we show that tt¯+missing energy and monojet searches are suitable probes in the limit where the dark energy scalar is stable... Read More about LHC signatures of scalar dark energy.

A proposed experimental search for chameleons using asymmetric parallel plates (2016)
Journal Article
Burrage, C., Copeland, E. J., & Stevenson, J. A. (2016). A proposed experimental search for chameleons using asymmetric parallel plates. Journal of Cosmology and Astroparticle Physics, 2016(8), https://doi.org/10.1088/1475-7516/2016/08/070

Light scalar fields coupled to matter are a common consequence of theories of dark energy and attempts to solve the cosmological constant problem. The chameleon screening mechanism is commonly invoked in order to suppress the fifth forces mediated by... Read More about A proposed experimental search for chameleons using asymmetric parallel plates.

Disformal transformations on the CMB (2016)
Journal Article
Burrage, C., Cespedes, S., & Davis, A.-C. (2016). Disformal transformations on the CMB. Journal of Cosmology and Astroparticle Physics, 2016, https://doi.org/10.1088/1475-7516/2016/08/024

In this work we study the role of disformal transformation on cosmological backgrounds and its relation to the speed of sound for tensor modes. A speed different from one for tensor modes can arise in several contexts, such as Galileons theories or m... Read More about Disformal transformations on the CMB.

Vacuum Cherenkov radiation and bremsstrahlung from disformal couplings (2016)
Journal Article
van de Bruck, C., Burrage, C., & Morrice, J. (2016). Vacuum Cherenkov radiation and bremsstrahlung from disformal couplings. Journal of Cosmology and Astroparticle Physics, 2016(8), Article 003. https://doi.org/10.1088/1475-7516/2016/08/003

The simplest way to modify gravity is to extend the gravitational sector to include an additional scalar degree of freedom. The most general metric that can be built in such a theory includes disformal terms, so that standard model fields move on a m... Read More about Vacuum Cherenkov radiation and bremsstrahlung from disformal couplings.

The speed of Galileon gravity (2016)
Journal Article
Brax, P., Burrage, C., & Davis, A.-C. (2016). The speed of Galileon gravity. Journal of Cosmology and Astroparticle Physics, 2016(3), Article 004. https://doi.org/10.1088/1475-7516/2016/03/004

We analyse the speed of gravitational waves in coupled Galileon models with an equation of state ωphgr=−1 now and a ghost-free Minkowski limit. We find that the gravitational waves propagate much faster than the speed of light unless these models are... Read More about The speed of Galileon gravity.