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Dynamical simulations of electroweak baryogenesis with fermions (2012)
Journal Article
Saffin, P. M., & Tranberg, A. (2012). Dynamical simulations of electroweak baryogenesis with fermions. Journal of High Energy Physics, 2012(2), Article 102. https://doi.org/10.1007/JHEP02%282012%29102

We perform real-time numerical lattice simulations of a one-family version of the Standard Model. We model the quantum fermions using the ensemble method and treat the bosonic scalar and non-abelian gauge fields classically. Our main interest is elec... Read More about Dynamical simulations of electroweak baryogenesis with fermions.

General second-order scalar-tensor theory and self-tuning (2012)
Journal Article
Charmousis, C., Copeland, E. J., Saffin, P. M., & Padilla, A. (2012). General second-order scalar-tensor theory and self-tuning. Physical Review Letters, 108(5), Article 051101. https://doi.org/10.1103/PhysRevLett.108.051101

Starting from the most general scalar-tensor theory with second order field equations in four dimensions, we establish the unique action that will allow for the existence of a consistent self-tuning mechanism on FLRW backgrounds, and show how it can... Read More about General second-order scalar-tensor theory and self-tuning.

Improved measurements of the intergalactic medium temperature around quasars: possible evidence for the initial stages of He-II reionisation at z~6 (2012)
Journal Article
S. Bolton, J., D. Becker, G., Raskutti, S., Stuart B. Wyithe, J., G. Haehnelt, M., & L. W. Sargent, W. (2012). Improved measurements of the intergalactic medium temperature around quasars: possible evidence for the initial stages of He-II reionisation at z~6. Monthly Notices of the Royal Astronomical Society, 419(4), 2880–2892. https://doi.org/10.1111/j.1365-2966.2011.19929.x

We present measurements of the intergalactic medium (IGM) temperature within ~5 proper Mpc of seven luminous quasars at z~6. The constraints are obtained from the Doppler widths of Lyman-alpha absorption lines in the quasar near-zones and build upon... Read More about Improved measurements of the intergalactic medium temperature around quasars: possible evidence for the initial stages of He-II reionisation at z~6.

A novel receive-only liquid nitrogen (LN2)-cooled RF coil for high-resolution in vivo imaging on a 3-Tesla whole-body scanner (2012)
Journal Article
Hu, B., Varma, G., Randell, C., Keevil, S. F., Schaeffter, T., & Glover, P. (2012). A novel receive-only liquid nitrogen (LN2)-cooled RF coil for high-resolution in vivo imaging on a 3-Tesla whole-body scanner. IEEE Transactions on Instrumentation and Measurement, 61(1), https://doi.org/10.1109/TIM.2011.2157575

The design and operation of a receive-only liquid nitrogen (LN2)-cooled coil and cryostat suitable for medical imaging on a 3-T whole-body magnetic resonance scanner is presented. The coil size, optimized for murine imaging, was determined by using... Read More about A novel receive-only liquid nitrogen (LN2)-cooled RF coil for high-resolution in vivo imaging on a 3-Tesla whole-body scanner.

Magnetic field effects on the vestibular system: calculation of the pressure on the cupula due to ionic current-induced Lorentz force (2012)
Journal Article
Antunes, A., Glover, P., Li, Y., Mian, O., & Day, B. (2012). Magnetic field effects on the vestibular system: calculation of the pressure on the cupula due to ionic current-induced Lorentz force. Physics in Medicine and Biology, 57(14), https://doi.org/10.1088/0031-9155/57/14/4477

Large static magnetic fields may be employed in magnetic resonance imaging (MRI). At high magnetic field strengths (usually from about 3 tesla and above) it is possible for humans to perceive a number of effects. One such effect is mild vertigo. Rece... Read More about Magnetic field effects on the vestibular system: calculation of the pressure on the cupula due to ionic current-induced Lorentz force.

Fast, large-volume, GPU-enabled simulations for the Lyα forest: power spectrum forecasts for baryon acoustic oscillation experiments (2011)
Journal Article
(2011). Fast, large-volume, GPU-enabled simulations for the Lyα forest: power spectrum forecasts for baryon acoustic oscillation experiments. Monthly Notices of the Royal Astronomical Society, 418(3), 1980-1993. https://doi.org/10.1111/j.1365-2966.2011.19617.x

High-redshift measurements of the baryonic acoustic oscillation (BAO) scale from large Lyα forest surveys represent the next frontier of dark energy studies. As part of this effort, efficient simulations of the BAO signature from the Lyα forest will... Read More about Fast, large-volume, GPU-enabled simulations for the Lyα forest: power spectrum forecasts for baryon acoustic oscillation experiments.

Amplifying single impurities immersed in a gas of ultracold atoms (2011)
Journal Article
Olmos, B., Li, W., Hofferberth, S., & Lesanovsky, I. (2011). Amplifying single impurities immersed in a gas of ultracold atoms. Physical Review A, 84(4), Article 041607(R). https://doi.org/10.1103/PhysRevA.84.041607

We present a method for amplifying a single or scattered impurities immersed in a background gas of ultracold atoms so that they can be optically imaged and spatially resolved. Our approach relies on a Raman transfer between two stable atomic hyperfi... Read More about Amplifying single impurities immersed in a gas of ultracold atoms.

Reducing heterotic M-theory to five dimensional supergravity on a manifold with boundary (2011)
Journal Article
Moss, I. G., Omotani, J. T., & Saffin, P. M. (2011). Reducing heterotic M-theory to five dimensional supergravity on a manifold with boundary. Journal of High Energy Physics, 2011(10), https://doi.org/10.1007/JHEP10%282011%29088

This paper constructs the reduction of heterotic M-theory in eleven dimensions to a supergravity model on a manifold with boundary in five dimensions using a Calabi-Yau three-fold. New results are presented for the boundary terms in the action and fo... Read More about Reducing heterotic M-theory to five dimensional supergravity on a manifold with boundary.

Colliding branes and big crunches (2011)
Journal Article
Omotani, J., Saffin, P. M., & Louko, J. (2011). Colliding branes and big crunches. Physical Review D, 84(6), Article 063526. https://doi.org/10.1103/PhysRevD.84.063526

We examine the global structure of colliding domain walls in AdS spacetime and come to the conclusion that singularities forming from such collisions are of the big-crunch type rather than that of a black brane.

How neutral is the intergalactic medium surrounding the redshift z=7.085 quasar ULAS J1120+0641? (2011)
Journal Article
S. Bolton, J., G. Haehnelt, M., J. Warren, S., C. Hewett, P., J. Mortlock, D., P. Venemans, B., …Simpson, C. (2011). How neutral is the intergalactic medium surrounding the redshift z=7.085 quasar ULAS J1120+0641?. Monthly Notices of the Royal Astronomical Society: Letters, 416(1), L70–L74. https://doi.org/10.1111/j.1745-3933.2011.01100.x

The quasar ULAS J1120+0641 at redshift z=7.085 has a highly ionised near zone which is smaller than those around quasars of similar luminosity at z~6. The spectrum also exhibits evidence for a damping wing extending redward of the systemic Lya redshi... Read More about How neutral is the intergalactic medium surrounding the redshift z=7.085 quasar ULAS J1120+0641?.

Real-time fermions for baryogenesis simulations (2011)
Journal Article
Saffin, P. M., & Tranberg, A. (2011). Real-time fermions for baryogenesis simulations. Journal of High Energy Physics, 2011(7), https://doi.org/10.1007/JHEP07%282011%29066

We study how to numerically simulate quantum fermions out of thermal equilibrium, in the context of electroweak baryogenesis. We find that by combining the lattice implementation of Aarts and Smit [1] with the "low cost" fermions of Borsanyi and Hind... Read More about Real-time fermions for baryogenesis simulations.

The impact of spatial fluctuations in the ultra-violet background on intergalactic carbon and silicon (2011)
Journal Article
S. Bolton, J., & Viel, M. (2011). The impact of spatial fluctuations in the ultra-violet background on intergalactic carbon and silicon. Monthly Notices of the Royal Astronomical Society, 414(1), 241–252. https://doi.org/10.1111/j.1365-2966.2011.18384.x

Spatial inhomogeneities in the spectral shape of the ultra-violet background (UVB) at the tail-end of HeII reionisation are thought to be the primary cause of the large fluctuations observed in the HeII to HI Ly-a forest optical depth ratio, tau_HeII... Read More about The impact of spatial fluctuations in the ultra-violet background on intergalactic carbon and silicon.

Measurements of the ultraviolet background at 4.6 < z < 6.4 using the quasar proximity effect (2011)
Journal Article
(2011). Measurements of the ultraviolet background at 4.6 < z < 6.4 using the quasar proximity effect. Monthly Notices of the Royal Astronomical Society, 412(4), 2543-2562. https://doi.org/10.1111/j.1365-2966.2010.18072.x

We present measurements of the ionizing ultraviolet background (UVB) at z∼ 5–6 using the quasar proximity effect. The 15 quasars in our sample cover the range 4.6 < zq < 6.4, enabling the first proximity-effect measurements of the UVB at z > 5. The m... Read More about Measurements of the ultraviolet background at 4.6 < z < 6.4 using the quasar proximity effect.

Multi-Galileons, solitons, and Derrick’s theorem (2011)
Journal Article
Padilla, A., Saffin, P. M., & Zhou, S.-Y. (2011). Multi-Galileons, solitons, and Derrick’s theorem. Physical Review D, 83(4), https://doi.org/10.1103/PhysRevD.83.045009

The field theory Galilean symmetry, which was introduced in the context of modified gravity, gives a neat way to construct Lorentz-covariant theories of a scalar field, such that the equations of motion contain at most second-order derivatives. Here... Read More about Multi-Galileons, solitons, and Derrick’s theorem.

Bi-galileon theory II: phenomenology (2011)
Journal Article
Padilla, A., Saffin, P. M., & Zhou, S.-Y. (2011). Bi-galileon theory II: phenomenology. Journal of High Energy Physics, 2011(1), https://doi.org/10.1007/JHEP01%282011%29099

We continue to introduce bi-galileon theory, the generalisation of the single galileon model introduced by Nicolis et al. The theory contains two coupled scalar fields and is described by a Lagrangian that is invariant under Galilean shifts in those... Read More about Bi-galileon theory II: phenomenology.

Reducing the gradient artefact in simultaneous EEG-fMRI by adjusting the subject’s axial position (2011)
Journal Article
Mullinger, K. J., Yan, W. X., & Bowtell, R. W. (2011). Reducing the gradient artefact in simultaneous EEG-fMRI by adjusting the subject’s axial position. NeuroImage, 54(3), https://doi.org/10.1016/j.neuroimage.2010.09.079

Large artefacts which compromise EEG data quality are generated when electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) are carried out concurrently. The gradient artefact produced by the time-varying magnetic field gradien... Read More about Reducing the gradient artefact in simultaneous EEG-fMRI by adjusting the subject’s axial position.

Galaxy Zoo 1 : Data Release of Morphological Classifications for nearly 900,000 galaxies (2010)
Journal Article
Lintott, C., Schawinski, K., Bamford, S., Slosar, A., Land, K., Thomas, D., …Vandenberg, J. (2011). Galaxy Zoo 1 : Data Release of Morphological Classifications for nearly 900,000 galaxies. Monthly Notices of the Royal Astronomical Society, 410(1), 166–178. https://doi.org/10.1111/j.1365-2966.2010.17432.x

Morphology is a powerful indicator of a galaxy's dynamical and merger history. It is strongly correlated with many physical parameters, including mass, star formation history and the distribution of mass. The Galaxy Zoo project collected simple morph... Read More about Galaxy Zoo 1 : Data Release of Morphological Classifications for nearly 900,000 galaxies.

Bi-galileon theory I: motivation and formulation (2010)
Journal Article
Padilla, A., Saffin, P. M., & Zhou, S.-Y. (2010). Bi-galileon theory I: motivation and formulation. Journal of High Energy Physics, 2010(12), https://doi.org/10.1007/JHEP12%282010%29031

We introduce bi-galileon theory, the generalisation of the single galileon model introduced by Nicolis et al. The theory contains two coupled scalar fields and is described by a Lagrangian that is invariant under Galilean shifts in those fields. This... Read More about Bi-galileon theory I: motivation and formulation.