Skip to main content

Research Repository

Advanced Search

All Outputs (42)

Quasi-normal modes and fermionic vacuum decay around a Kerr black hole (2019)
Journal Article
Coutant, A., & Millington, P. (2019). Quasi-normal modes and fermionic vacuum decay around a Kerr black hole. Classical and Quantum Gravity, 36(3), Article 035005. https://doi.org/10.1088/1361-6382/aaf679

We analyze the instability of the non-rotating fermion vacuum in Kerr spacetimes. We describe how the co-rotating Fermi sea is formed as a result of a spontaneous vacuum decay. Most significantly, and drawing upon intuition gained from analogous elec... Read More about Quasi-normal modes and fermionic vacuum decay around a Kerr black hole.

Fifth forces, Higgs portals and broken scale invariance (2018)
Journal Article
Burrage, C., Copeland, E. J., Millington, P., & Spannowsky, M. (2018). Fifth forces, Higgs portals and broken scale invariance. Journal of Cosmology and Astroparticle Physics, 2018(11), 1-31. https://doi.org/10.1088/1475-7516/2018/11/036

© 2018 IOP Publishing Ltd and Sissa Medialab. We study the relationship between the strength of fifth forces and the origin of scale breaking in the Standard Model (SM) of particle physics. We start with a light scalar field that is conformally coupl... Read More about Fifth forces, Higgs portals and broken scale invariance.

Radiative effects on false vacuum decay in Higgs-Yukawa theory (2018)
Journal Article
Ai, W., Garbrecht, B., & Millington, P. (2018). Radiative effects on false vacuum decay in Higgs-Yukawa theory. Physical Review D, 98(7), Article 076014. https://doi.org/10.1103/physrevd.98.076014

We derive fermionic Green’s functions in the background of the Euclidean solitons describing false vacuum decay in a prototypal Higgs-Yukawa theory. In combination with appropriate counterterms for the masses, couplings and wave-function normalizatio... Read More about Radiative effects on false vacuum decay in Higgs-Yukawa theory.

Boltzmann equations for preheating (2018)
Journal Article
Emond, W. T., Millington, P., & Saffin, P. M. (2018). Boltzmann equations for preheating. Journal of Cosmology and Astroparticle Physics, 2018(09), doi:10.1088/1475-7516/2018/09/041

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 collisional processes between the produced particles. In so doing, we illustra... Read More about Boltzmann equations for preheating.

Spontaneous symmetry breaking and the Goldstone theorem in non-Hermitian field theories (2018)
Journal Article
Alexandre, J., Ellis, J., Millington, P., & Seynaeve, D. (2018). Spontaneous symmetry breaking and the Goldstone theorem in non-Hermitian field theories. Physical Review D, 98(4), Article 5001. https://doi.org/10.1103/physrevd.98.045001

We demonstrate the extension to parity-time (PT)-symmetric field theories of the Goldstone theorem, confirming that the spontaneous appearance of a field vacuum expectation value via minimization of the effective potential in a non-Hermitian model is... Read More about Spontaneous symmetry breaking and the Goldstone theorem in non-Hermitian field theories.

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.

Fluctuations about the Fubini-Lipatov instanton for false vacuum decay in classically scale invariant models (2018)
Journal Article
Garbrecht, B., & Millington, P. (in press). Fluctuations about the Fubini-Lipatov instanton for false vacuum decay in classically scale invariant models. Physical Review D, 98(1), Article 016001. https://doi.org/10.1103/PhysRevD.98.016001

For a scalar theory whose classical scale invariance is broken by quantum effects, we compute self-consistent bounce solutions and Green's functions. Deriving analytic expressions, we find that the latter are similar to the Green's functions in the a... Read More about Fluctuations about the Fubini-Lipatov instanton for false vacuum decay in classically scale invariant models.

Resonant enhancement in leptogenesis (2018)
Journal Article
Dev, P., Garny, M., Klaric, J., Millington, P., & Teresi, D. (2018). Resonant enhancement in leptogenesis. International Journal of Modern Physics A, 33(05n06), https://doi.org/10.1142/S0217751X18420034

Vanilla leptogenesis within the type I seesaw framework requires the mass scale of the right-handed neutrinos to be above 109 GeV. This lower bound can be avoided if at least two of the sterile states are almost mass degenerate, which leads to an enh... Read More about Resonant enhancement in leptogenesis.

Flavor effects in leptogenesis (2018)
Journal Article
Dev, P., Di Bari, P., Garbrecht, B., Lavignac, S., Millington, P., & Teresi, D. (2018). Flavor effects in leptogenesis. International Journal of Modern Physics A, 33(05n06), https://doi.org/10.1142/S0217751X18420010

Flavor effects can have a significant impact on the final estimate of the lepton (and therefore baryon) asymmetry in scenarios of leptogenesis. It is therefore necessary to account fully for this flavor dynamics in the relevant transport equations th... Read More about Flavor effects in leptogenesis.

Status of rates and rate equations for thermal leptogenesis (2018)
Journal Article
Biondini, S., Bödeker, D., Brambilla, N., Garny, M., Ghiglieri, J., Hohenegger, A., …Vairo, A. (2018). Status of rates and rate equations for thermal leptogenesis. International Journal of Modern Physics A, 33(05n06), https://doi.org/10.1142/S0217751X18420046

In many realizations of leptogenesis, heavy right-handed neutrinos play the main role in the generation of an imbalance between matter and antimatter in the early Universe. Hence, it is relevant to address quantitatively their dynamics in a hot and d... Read More about Status of rates and rate equations for thermal leptogenesis.

Consistent description of field theories with non-Hermitian mass terms (2018)
Journal Article
Alexandre, J., Millington, P., & Seynaeve, D. (2018). Consistent description of field theories with non-Hermitian mass terms. Journal of Physics: Conference Series, 952, https://doi.org/10.1088/1742-6596/952/1/012012

We review how to describe a field theory that includes a non-Hermitian mass term in the region of parameter space where the Lagrangian is PT-symmetric. The discrete symmetries of the system are essential for understanding the consistency of the model... Read More about Consistent description of field theories with non-Hermitian mass terms.

Fock-space projection operators for semi-inclusive final states (2017)
Journal Article
Dickinson, R., Forshaw, J., & Millington, P. (2017). Fock-space projection operators for semi-inclusive final states. Physics Letters B, 774, https://doi.org/10.1016/j.physletb.2017.10.037

We present explicit expressions for Fock-space projection operators that correspond to realistic final states in scattering experiments. Our operators automatically sum over unobserved quanta and account for non-emission into sub-regions of momentum... Read More about Fock-space projection operators for semi-inclusive final states.

Symmetries and conservation laws in non-Hermitian field theories (2017)
Journal Article
Alexandre, J., Millington, P., & Seynaeve, D. (2017). Symmetries and conservation laws in non-Hermitian field theories. Physical Review D, 96(6), https://doi.org/10.1103/PhysRevD.96.065027

Anti-Hermitian mass terms are considered, in addition to Hermitian ones, for PT-symmetric complex-scalar and fermionic field theories. In both cases, the Lagrangian can be written in a manifestly symmetric form in terms of the PT-conjugate variables,... Read More about Symmetries and conservation laws in non-Hermitian field theories.

Working directly with probabilities in quantum field theory (2017)
Journal Article
Dickinson, R., Forshaw, J., & Millington, P. (2017). Working directly with probabilities in quantum field theory. Journal of Physics: Conference Series, 880(1), Article 012041. https://doi.org/10.1088/1742-6596/880/1/012041

We present a novel approach to computing transition probabilities in quantum field theory, which allows them to be written directly in terms of expectation values of nested commutators and anti-commutators of field operators, rather than squared matr... Read More about Working directly with probabilities in quantum field theory.

Self-consistent radiative corrections to false vacuum decay (2017)
Journal Article
Garbrecht, B., & Millington, P. (in press). Self-consistent radiative corrections to false vacuum decay. Journal of Physics: Conference Series, 873, Article 012041. https://doi.org/10.1088/1742-6596/873/1/012041

With the Higgs mass now measured at the sub-percent level, the potential metastability of the electroweak vacuum of the Standard Model (SM) motivates renewed study of false vacuum decay in quantum field theory. In this note, we describe an approach t... Read More about Self-consistent radiative corrections to false vacuum decay.

Light neutrino masses from a non-Hermitian Yukawa theory (2017)
Journal Article
Alexandre, J., Bender, C. M., & Millington, P. (2017). Light neutrino masses from a non-Hermitian Yukawa theory. Journal of Physics: Conference Series, 873, Article 012047. https://doi.org/10.1088/1742-6596/873/1/012047

Working within the context of PT-symmetric quantum mechanics, we begin by describing a non-Hermitian extension of QED that is both Lorentz invariant and consistent with unitarity. We show that the non-Hermitian Dirac mass matrix of this theory exhibi... Read More about Light neutrino masses from a non-Hermitian Yukawa theory.

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.

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.

Lepton asymmetry from mixing and oscillations (2016)
Journal Article
Kartavtsev, A., Millington, P., & Vogel, H. (2016). Lepton asymmetry from mixing and oscillations. Journal of High Energy Physics, 2016(6), Article 66. https://doi.org/10.1007/JHEP06%282016%29066

We show how the two physically-distinct sources of CP-asymmetry relevant to scenarios of leptogenesis: (i) resonant mixing and (ii) oscillations between different flavours can be unambiguously identified within the Kadanoff-Baym formalism. These cont... Read More about Lepton asymmetry from mixing and oscillations.

Probabilities and signalling in quantum field theory (2016)
Journal Article
Dickinson, R., Forshaw, J., & Millington, P. (2016). Probabilities and signalling in quantum field theory. Physical Review D, 93(6), Article 065054. https://doi.org/10.1103/PhysRevD.93.065054

We present an approach to computing probabilities in quantum field theory for a wide class of source-detector models. The approach works directly with probabilities and not with squared matrix elements, and the resulting probabilities can be written... Read More about Probabilities and signalling in quantum field theory.