Outputs (70)

Erratum: Alternative flow equation for the functional renormalization group [Phys. Rev. D 100, 101702(R) (2019)] (2021)
Journal Article
Alexander, E., Millington, P., Nursey, J., & Saffin, P. M. (2021). Erratum: Alternative flow equation for the functional renormalization group [Phys. Rev. D 100, 101702(R) (2019)]. Physical Review D, 104(6), Article 069906. https://doi.org/10.1103/physrevd.104.069906

We correct the functional identity reported in our paper for the inverse two-point function, as obtained from the 2PI effective action. The original conclusions are otherwise unaffected. The 2PI effective action is convex with respect to the variable... Read More about Erratum: Alternative flow equation for the functional renormalization group [Phys. Rev. D 100, 101702(R) (2019)].

Gravitational collapse with quantum fields (2021)
Journal Article
Berczi, B., Saffin, P. M., & Zhou, S.-Y. (2021). Gravitational collapse with quantum fields. Physical Review D, 104(4), Article L041703. https://doi.org/10.1103/PhysRevD.104.L041703

Gravitational collapse into a black hole has been extensively studied with classical sources. We develop a new formalism to simulate quantum fields forming a black hole. This formalism utilizes well-established techniques used for classical collapse... Read More about Gravitational collapse with quantum fields.

Charge-Swapping Q-balls and Their Lifetimes (2021)
Journal Article
Xie, Q.-X., Saffin, P. M., & Zhou, S.-Y. (2021). Charge-Swapping Q-balls and Their Lifetimes. Journal of High Energy Physics, 2021(7), Article 62. https://doi.org/10.1007/jhep07%282021%29062

For scalar theories accommodating spherically symmetric Q-balls, there are also towers of quasi-stable composite Q-balls, called charge swapping Q-balls (CSQs). We investigate the properties, particularly the lifetimes, of these long-lived CSQs in 2+... Read More about Charge-Swapping Q-balls and Their Lifetimes.

Dipole radiation and beyond from axion stars in electromagnetic fields (2021)
Journal Article
Amin, M. A., Long, A. J., Mou, Z., & Saffin, P. M. (2021). Dipole radiation and beyond from axion stars in electromagnetic fields. Journal of High Energy Physics, 2021(6), Article 182. https://doi.org/10.1007/jhep06%282021%29182

We investigate the production of photons from coherently oscillating, spatially localized clumps of axionic fields (oscillons and axion stars) in the presence of external electromagnetic fields. We delineate different qualitative behaviour of the pho... Read More about Dipole radiation and beyond from axion stars in electromagnetic fields.

Deconstructing higher order clockwork gravity (2021)
Journal Article
Avgoustidis, A., Niedermann, F., Padilla, A., & Saffin, P. M. (2021). Deconstructing higher order clockwork gravity. Physical Review D, 103(12), Article 124007. https://doi.org/10.1103/physrevd.103.124007

We consider the higher order clockwork theory of gravitational interactions, whereby a number of gravitons are coupled together with TeV strength, but nevertheless generate a Planck scale coupling to matter without the need for a dilaton. It is shown... Read More about Deconstructing higher order clockwork gravity.

Statistics on Lefschetz thimbles: Bell/Leggett-Garg inequalities and the classical-statistical approximation (2021)
Journal Article
Millington, P., Mou, Z.-G., Saffin, P. M., & Tranberg, A. (2021). Statistics on Lefschetz thimbles: Bell/Leggett-Garg inequalities and the classical-statistical approximation. Journal of High Energy Physics, 2021(3), Article 77. https://doi.org/10.1007/jhep03%282021%29077

Inspired by Lefschetz thimble theory, we treat Quantum Field Theory as a statistical theory with a complex Probability Distribution Function (PDF). Such complex-valued PDFs permit the violation of Bell-type inequalities, which cannot be violated by a... Read More about Statistics on Lefschetz thimbles: Bell/Leggett-Garg inequalities and the classical-statistical approximation.

Simulations of a bubble wall interacting with an electroweak plasma (2021)
Journal Article
Mou, Z.-G., Saffin, P. M., & Tranberg, A. (2021). Simulations of a bubble wall interacting with an electroweak plasma. Journal of High Energy Physics, 2021(2), Article 189. https://doi.org/10.1007/jhep02%282021%29189

We perform large-scale real-time simulations of a bubble wall sweeping through an out-of-equilibrium plasma. The scenario we have in mind is the electroweak phase transition, which may be first order in extensions of the Standard Model, and produce s... Read More about Simulations of a bubble wall interacting with an electroweak plasma.

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.

Black holes in self-tuning cubic Horndeski cosmology (2020)
Journal Article
Emond, W. T., Lehébel, A., & Saffin, P. M. (2020). Black holes in self-tuning cubic Horndeski cosmology. Physical Review D, 101(8), Article 084008. https://doi.org/10.1103/physrevd.101.084008

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 within the “self-tuning” class of this restricted set, whereby the bar... Read More about Black holes in self-tuning cubic Horndeski cosmology.

Alternative flow equation for the functional renormalization group (2019)
Journal Article
Alexander, E., Millington, P., Nursey, J., & Saffin, P. M. (2019). Alternative flow equation for the functional renormalization group. Physical Review D, 100(10), Article 101702(R). https://doi.org/10.1103/physrevd.100.101702

We derive an alternative to the Wetterich-Morris-Ellwanger equation by means of the two-particle irreducible (2PI) effective action, exploiting the method of external sources due to Garbrecht and Millington. The latter allows the two-point source of... Read More about Alternative flow equation for the functional renormalization group.