Outputs (38)

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.

Cosmological consequences of Omnia Sequestra (2019)
Journal Article
Coltman, B., Li, Y., & Padilla, A. (2019). Cosmological consequences of Omnia Sequestra. Journal of Cosmology and Astroparticle Physics, 2019(06), https://doi.org/10.1088/1475-7516/2019/06/017

Vacuum energy sequestering is a mechanism for cancelling off the radiative corrections to vacuum energy. The most comprehensive low energy model, proposed in [1], has the ability to cancel off radiative corrections to vacuum energy for loops of both... Read More about Cosmological consequences of Omnia Sequestra.

Dark Energy after GW170817 Revisited (2019)
Journal Article
Copeland, E. J., Kopp, M., Padilla, A., Saffin, P. M., & Skordis, C. (2019). Dark Energy after GW170817 Revisited. Physical Review Letters, 122(6), Article 061301. https://doi.org/10.1103/physrevlett.122.061301

We revisit the status of scalar-tensor theories with applications to dark energy in the aftermath of the gravitational wave signal GW170817 and its optical counterpart GRB170817A. At the level of the cosmological background, we identify a class of th... Read More about Dark Energy after GW170817 Revisited.

Higher order clockwork gravity (2018)
Journal Article
Niedermann, F., Padilla, A., & Saffin, P. M. (2018). Higher order clockwork gravity. Physical Review D, 98(10), Article 104014. https://doi.org/10.1103/physrevd.98.104014

We present a higher order generalisation of the clockwork mechanism starting from an underlying non-linear multigravity theory with a single scale and nearest neighbour ghost-free interactions. Without introducing any hierarchies in the underlying po... Read More about Higher order clockwork gravity.

Non-perturbative aspects of galileon duality (2018)
Journal Article
Millington, P., Niedermann, F., & Padilla, A. (in press). Non-perturbative aspects of galileon duality. European Physical Journal C: Particles and Fields, 78(7), https://doi.org/10.1140/epjc/s10052-018-6029-0

We study quantum aspects of the galileon duality, especially in the case of a particular interacting galileon theory that is said to be dual to a free theory through the action of a simultaneous field and coordinate transformation. This would appear... Read More about Non-perturbative aspects of galileon duality.

Vainshtein in the UV and a Wilsonian analysis of derivatively coupled scalars (2018)
Journal Article
Padilla Antonio, A., & Saltas, I. (2018). Vainshtein in the UV and a Wilsonian analysis of derivatively coupled scalars. Journal of Cosmology and Astroparticle Physics, 2018(6), https://doi.org/10.1088/1475-7516/2018/06/039

In the first part of this paper we critically examine the ultra-violet implications of theories that exhibit Vainshtein screening, taking into account both the standard Wilsonian perspective as well as more exotic possibilities. Aspects of this discu... Read More about Vainshtein in the UV and a Wilsonian analysis of derivatively coupled scalars.

Gravitational mechanisms to self-tune the cosmological constant: obstructions and ways forward (2017)
Journal Article
Niedermann, F., & Padilla, A. (2017). Gravitational mechanisms to self-tune the cosmological constant: obstructions and ways forward. Physical Review Letters, 119(25), Article 251306. https://doi.org/10.1103/PhysRevLett.119.251306

Gravitational models of self-tuning are those in which vacuum energy has no observable effect on spacetime curvature, even though it is a priori unsuppressed below the cut-off. We complement Weinberg's no go theorem by studying field theoretic comple... Read More about Gravitational mechanisms to self-tune the cosmological constant: obstructions and ways forward.

An étude on global vacuum energy sequester (2017)
Journal Article
D’Amico, G., Kaloper, N., Padilla, A., Stefanyszyn, D., Westphal, A., & Zahariade, G. (2017). An étude on global vacuum energy sequester. Journal of High Energy Physics, 2017(9), Article 74. https://doi.org/10.1007/JHEP09%282017%29074

Recently two of the authors proposed a mechanism of vacuum energy sequester as a means of protecting the observable cosmological constant from quantum radiative corrections. The original proposal was based on using global Lagrange multipliers, but la... Read More about An étude on global vacuum energy sequester.

Probing scalar effective field theories with the soft limits of scattering amplitudes (2017)
Journal Article
Padilla, A., Stefanyszyn, D., & Wilson, T. (2017). Probing scalar effective field theories with the soft limits of scattering amplitudes. Journal of High Energy Physics, 2017(4), https://doi.org/10.1007/JHEP04%282017%29015

We investigate the soft behaviour of scalar effective field theories (EFTs) when there is a number of distinct derivative power counting parameters, ?1 < ?2 < . . . < ?Q. We clarify the notion of an enhanced soft limit and use these to extend the sco... Read More about Probing scalar effective field theories with the soft limits of scattering amplitudes.

Vacuum energy sequestering and graviton loops (2017)
Journal Article
Kaloper, N., & Padilla, A. (2017). Vacuum energy sequestering and graviton loops. Physical Review Letters, 118(6), Article 061303. https://doi.org/10.1103/PhysRevLett.118.061303

We recently formulated a local mechanism of vacuum energy sequester. This mechanism automatically removes all matter loop contributions to vacuum energy from the stress energy tensor which sources the curvature. Here we adapt the local vacuum energy... Read More about Vacuum energy sequestering and graviton loops.