All Outputs (2073)

The evolution of conifolds (2008)
Journal Article
Butcher, N. A., & Saffin, P. M. (2008). The evolution of conifolds. Journal of High Energy Physics, 2008(12), https://doi.org/10.1088/1126-6708/2008/12/012

We simulate the gravitational dynamics of the conifold geometries (resolved and deformed) involved in the description of certain compact spacetimes. As the cycles of the conifold collapse towards a singular geometry we find that a horizon develops, s... Read More about The evolution of conifolds.

Some stationary properties of a Q-ball in arbitrary space dimensions (2008)
Journal Article
Tsumagari, M. I., Copeland, E. J., & Saffin, P. M. (2008). Some stationary properties of a Q-ball in arbitrary space dimensions. Physical Review D, 78(6), https://doi.org/10.1103/PhysRevD.78.065021

Introducing new physically motivated ansaetze, we explore both analytically and numerically the classical and absolute stabilities of a single Q-ball in an arbitrary number of spatial dimensions D, working in both the thin and thick wall limits.

Transmission of an inhomogeneous state via resonant tunnelling (2008)
Journal Article
Saffin, P. M., Padilla, A., & Copeland, E. J. (2008). Transmission of an inhomogeneous state via resonant tunnelling. Journal of High Energy Physics, 2008(9), https://doi.org/10.1088/1126-6708/2008/09/055

We recently investigated the nature of resonant tunnelling in standard scalar Quantum Field Theory, uncovering the conditions required for resonance. It was shown that whereas the homogeneous false vacuum may decay via bubble nucleation, it may not d... Read More about Transmission of an inhomogeneous state via resonant tunnelling.

Cosmic string Y-junctions: a comparison between field theoretic and Nambu-Goto dynamics (2008)
Journal Article
Bevis, N., & Saffin, P. M. (2008). Cosmic string Y-junctions: a comparison between field theoretic and Nambu-Goto dynamics. Physical Review D, 78(2), https://doi.org/10.1103/PhysRevD.78.023503

We explore the formation of cosmic string Y-junctions when strings of two different types collide, which has recently become important since string theory can yield cosmic strings of distinct types. Using a model containing two types of local U(1) st... Read More about Cosmic string Y-junctions: a comparison between field theoretic and Nambu-Goto dynamics.

Fingering Instabilities in Dewetting Nanofluids (2008)
Journal Article
Pauliac-Vaujour, E., Stannard, A., Martin, C., Blunt, M., Notingher, I., Moriarty, P., …Thiele, U. (2008). Fingering Instabilities in Dewetting Nanofluids. Physical Review Letters, 100,

The growth of fingering patterns in dewetting nanofluids (colloidal solutions of thiol-passivated gold nanoparticles) has been followed in real time using contrast-enhanced video microscopy. The fingering instability on which we focus here arises fro... Read More about Fingering Instabilities in Dewetting Nanofluids.

Possible evidence for an inverted temperature-density relation in the intergalactic medium from the flux distribution of the Lyman-alpha forest (2008)
Journal Article
S. Bolton, J., Viel, M., -S. Kim, T., G. Haehnelt, M., & F. Carswell, R. (2008). Possible evidence for an inverted temperature-density relation in the intergalactic medium from the flux distribution of the Lyman-alpha forest. Monthly Notices of the Royal Astronomical Society, 386(2), 1131-1144. https://doi.org/10.1111/j.1365-2966.2008.13114.x

Reclaiming Academia from Post-academia (2008)
Journal Article
Moriarty, P. (2008). Reclaiming Academia from Post-academia. Nature Nanotechnology, 3,

Post-academic science, driven as it is by commercialisation and market forces, is fundamentally at odds with core academic principles. Publicly-funded academics have an obligation to carry out science for the public good, a responsibility which is in... Read More about Reclaiming Academia from Post-academia.

How Cold Is Cold Dark Matter? Small-Scales Constraints from the Flux Power Spectrum of the High-Redshift Lyman-α Forest (2008)
Journal Article
Viel, M., Becker, G. D., Bolton, J. S., Haehnelt, M. G., Rauch, M., & Sargent, W. L. (2008). How Cold Is Cold Dark Matter? Small-Scales Constraints from the Flux Power Spectrum of the High-Redshift Lyman-α Forest. Physical Review Letters, 100(4), Article 041304. https://doi.org/10.1103/PhysRevLett.100.041304

No resonant tunneling in standard scalar quantum field theory (2008)
Journal Article
Copeland, E. J., Padilla, A., & Saffin, P. M. (2008). No resonant tunneling in standard scalar quantum field theory. Journal of High Energy Physics, 2008(1), https://doi.org/10.1088/1126-6708/2008/01/066

We investigate the nature of resonant tunneling in Quantum Field Theory. Following the pioneering work of Banks, Bender and Wu, we describe quantum field theory in terms of infinite dimensional quantum mechanics and utilize the ``Most probable escape... Read More about No resonant tunneling in standard scalar quantum field theory.

The fermion spectrum in braneworld collisions (2007)
Journal Article
Saffin, P. M., & Tranberg, A. (2007). The fermion spectrum in braneworld collisions. Journal of High Energy Physics, 2007(12), https://doi.org/10.1088/1126-6708/2007/12/053

In braneworld collisions fermions originally localised on one brane can be transferred to another brane, or to a space-time boundary. By modelling branes as scalar field kinks we bounce them off boundaries and study resulting effects according to a b... Read More about The fermion spectrum in braneworld collisions.

Anisotropic Assembly of Colloidal Nanoparticles: Exploiting Substrate Crystallinity (2007)
Journal Article
Hayton, J., Pauliac-Vaujour, E., & Moriarty, P. (2007). Anisotropic Assembly of Colloidal Nanoparticles: Exploiting Substrate Crystallinity. NANO, 2(6), https://doi.org/10.1142/S1793292007000714

We show that the crystal structure of a substrate can be exploited to drive the anisotropic assembly of colloidal nanoparticles. Pentanethiol-passivated Au particles of approximately 2 nm diameter deposited from toluene onto hydrogen-passivated Si(11... Read More about Anisotropic Assembly of Colloidal Nanoparticles: Exploiting Substrate Crystallinity.

Reionization bias in high-redshift quasar near-zones (2007)
Journal Article
Wyithe, J. B., Bolton, J. S., & Haehnelt, M. G. (2007). Reionization bias in high-redshift quasar near-zones. Monthly Notices of the Royal Astronomical Society, 383(2), 691–704. https://doi.org/10.1111/j.1365-2966.2007.12578.x

Cosmology with twisted tori (2007)
Journal Article
Karthauser, J. L., Saffin, P., & Hindmarsh, M. (2007). Cosmology with twisted tori. Physical Review Letters, 76(10), https://doi.org/10.1103/PhysRevD.76.104039

We consider the cosmological role of the scalar fields generated by the compactification of 11-dimensional Einstein gravity on a 7D elliptic twisted torus, which has the attractive features of giving rise to a positive semi-definite potential, and pa... Read More about Cosmology with twisted tori.

An improved measurement of the flux distribution of the Ly-alpha forest in QSO absorption spectra: the effect of continuum fitting, metal contamination and noise properties (2007)
Journal Article
-S. Kim, T., S. Bolton, J., Viel, M., G. Haehnelt, M., & F. Carswell, R. (2007). An improved measurement of the flux distribution of the Ly-alpha forest in QSO absorption spectra: the effect of continuum fitting, metal contamination and noise properties. Monthly Notices of the Royal Astronomical Society, 382(4), 1657–1674. https://doi.org/10.1111/j.1365-2966.2007.12406.x

We have performed an extensive Voigt profile analysis of the neutral hydrogen (HI) and metal absorption present in a sample of 18 high resolution, high signal-to-noise QSO spectra observed with VLT/UVES. We use this analysis to separate the metal con... Read More about An improved measurement of the flux distribution of the Ly-alpha forest in QSO absorption spectra: the effect of continuum fitting, metal contamination and noise properties.

Singular manifolds, topology change and the dynamics of compactification (2007)
Journal Article
Butcher, N. A., & Saffin, P. M. (2007). Singular manifolds, topology change and the dynamics of compactification. Journal of High Energy Physics, 2007(11), https://doi.org/10.1088/1126-6708/2007/11/062

We investigate the dynamics of the geometric transitions associated to compactified spacetimes. By including the dynamics of gravity we are able to follow the evolution of collapsing cycles as they attempt to undergo a topology changing transition. R... Read More about Singular manifolds, topology change and the dynamics of compactification.

A closer look at using quasar near-zones as a probe of neutral hydrogen in the intergalactic medium (2007)
Journal Article
S. Bolton, J., & G. Haehnelt, M. (2007). A closer look at using quasar near-zones as a probe of neutral hydrogen in the intergalactic medium. Monthly Notices of the Royal Astronomical Society: Letters, 381(1), L35-L39. https://doi.org/10.1111/j.1745-3933.2007.00361.x

We examine a large set of synthetic quasar spectra to realistically assess the potential of using the relative sizes of highly ionized near-zones in the Lya and Lyb forest as a probe of the neutral hydrogen content of the intergalactic medium (IGM) a... Read More about A closer look at using quasar near-zones as a probe of neutral hydrogen in the intergalactic medium.

The observed ionization rate of the intergalactic medium and the ionizing emissivity at z >5: Evidence for a photon starved and extended epoch of reionization (2007)
Journal Article
S. Bolton, J., & G. Haehnelt, M. (2007). The observed ionization rate of the intergalactic medium and the ionizing emissivity at z >5: Evidence for a photon starved and extended epoch of reionization. Monthly Notices of the Royal Astronomical Society, 382(1), 325–341. https://doi.org/10.1111/j.1365-2966.2007.12372.x

We use a large set of hydrodynamical simulations, combined with measurements of the Lyman alpha opacity of the IGM taken from the literature, to obtain robust estimates for the photoionization rate per hydrogen atom at z=5 and 6. We find the photoion... Read More about The observed ionization rate of the intergalactic medium and the ionizing emissivity at z >5: Evidence for a photon starved and extended epoch of reionization.

Controlling Pattern Formation in Nanoparticle Assemblies via Directed Solvent Dewetting (2007)
Journal Article
Martin, C., Blunt, M., Pauliac-Vaujour, E., Stannard, A., Moriarty, P., Vancea, I., & Thiele, U. (2007). Controlling Pattern Formation in Nanoparticle Assemblies via Directed Solvent Dewetting. Physical Review Letters, 99,

We have achieved highly localised control of pattern formation in two dimensional nanoparticle assemblies by direct modification of solvent dewetting dynamics. A striking dependence of nanoparticle organisation on the size of atomic force microscope-... Read More about Controlling Pattern Formation in Nanoparticle Assemblies via Directed Solvent Dewetting.

Particle transfer in braneworld collisions (2007)
Journal Article
Saffin, P. M., & Tranberg, A. (2007). Particle transfer in braneworld collisions. Journal of High Energy Physics, 2007(8), https://doi.org/10.1088/1126-6708/2007/08/072

We study the behaviour of fermions localized on moving kinks as these collide with either antikinks or spacetime boundaries. We numerically solve for the evolution of the scalar kinks and the bound (i.e. localized) fermion modes, and calculate the nu... Read More about Particle transfer in braneworld collisions.

Coerced Mechanical Coarsening of Nanoparticle Assemblies (2007)
Journal Article
Blunt, M., Martin, C., Ahola-Tuomi, M., Pauliac-Vaujour, E., Sharp, P., Nativo, P., …Nativo, P. (2007). Coerced Mechanical Coarsening of Nanoparticle Assemblies. Nature Nanotechnology, 2, https://doi.org/10.1038/nnano.2007.25

Coarsening is a ubiquitous phenomenon [1-3] that underpins countless processes in nature, including epitaxial growth [1,3,4], the phase separation of alloys, polymers and binary fluids [2], the growth of bubbles in foams5, and pattern formation in bi... Read More about Coerced Mechanical Coarsening of Nanoparticle Assemblies.