Independently Parameterised Momenta Variables and Monte Carlo IR Subtraction

We introduce a system of parameters for the Monte Carlo generation of Lorentz invariant phase space that is particularly well-suited to the treatment of the infrared divergences that occur in the most singular, Born-like configurations of $1\to n$ QCD processes. A key feature is that particle momenta are generated independently of one another, leading to a simple parameterisation of all such IR limits. We exemplify the use of these variables in conjunction with the projection to Born subtraction technique at next-to-next-to-leading order. The geometric origins of this parameterisation lie in a coordinate chart on a Grassmannian manifold.Comment: 16 pages; v2: version published in JHE

Tipping points in open systems: bifurcation, noise-induced and rate-dependent examples in the climate system

Tipping points associated with bifurcations (B-tipping) or induced by noise (N-tipping) are recognized mechanisms that may potentially lead to sudden climate change. We focus here a novel class of tipping points, where a sufficiently rapid change to an input or parameter of a system may cause the system to "tip" or move away from a branch of attractors. Such rate-dependent tipping, or R-tipping, need not be associated with either bifurcations or noise. We present an example of all three types of tipping in a simple global energy balance model of the climate system, illustrating the possibility of dangerous rates of change even in the absence of noise and of bifurcations in the underlying quasi-static system.Comment: 20 pages, 8 figure

LHC Search for Right-handed Neutrinos in Z′Z^\prime Models

We consider right-handed neutrino pair production in generic $Z^\prime$ models. We propose a new, model-independent analysis using final states containing a pair of same-sign muons. A key aspect of this analysis is the reconstruction of the RH neutrino mass, which leads to a significantly improved sensitivity. Within the $U(1)_{(B-L)_{3}}$ model, we find that at the HL-LHC it will be possible to probe RH neutrino masses in the range $0.2\lesssim M_{N_R} \lesssim 1.1\,$TeV.Comment: 6 pages, 5 figure

A Soft-Wall Dilaton

We study the properties of the dilaton in a soft-wall background using two solutions of the Einstein equations. These solutions contain an asymptotically AdS metric with a nontrivial scalar profile that causes both the spontaneous breaking of conformal invariance and the generation of a mass gap in the particle spectrum. We first present an analytic solution, using the superpotential method, that describes a CFT spontaneously broken by a finite dimensional operator in which a light dilaton mode appears in the spectrum. This represents a tuning in the vanishing of the quartic coupling in the effective potential that could be naturally realised from an underlying supersymmetry. Instead, by considering a generalised analytic scalar bulk potential that quickly transitions at the condensate scale from a walking coupling in the UV to an order-one $\beta$-function in the IR, we obtain a naturally light dilaton. This provides a simple example for obtaining a naturally light dilaton from nearly-marginal CFT deformations in the more realistic case of a soft-wall background.Comment: 23 pages, 8 figures; v2: version published in JHE

The paradoxes of cyclotourism: Constructing and consuming nature

As an archetypal form of low carbon footprint travel, bicycle tourism appears on the surface to be an ideal candidate for sustainable tourism. Taking a longer historical view, however, one begins to become aware of complex paradoxes emerging from cyclotourist practices. Examination of cyclotourists’ own writings shows how nature and the natural have been successively constructed as an object of discourse. Two themes are of especial interest in this study. First, a discourse of wilderness and otherness is apparent as a key theme reinvented in differing forms by successive generations of riders and writers. Second, there is a parallel discourse of domestication at work in which nature and the natural become tamed and part of the human. Although apparently contradictory, these two themes are deeply intertwined in the literature: the cyclotourist is simultaneously both apart from the landscape and yet belongs in it. Further, the relationship between rider and the spaces ridden has had consequences in terms of the built environment as cyclists pioneered road improvements, transforming the object of their narrative. The paper draws principally on archival material from The Cyclists’ Touring Club (CTC) in the UK (founded 1878) to explore changing constructions of, and attitudes toward, ‘nature’. It chronicles changing attitudes and it analyses the production and reproduction of discourses and maps their transformation through the 20th century. In conclusion it also points to the ambiguities and contradictions inherent in contemporary cyclotourist practices as these have become much more closely enmeshed in the fossil fuel economy through changes in modes of activity

Postscript: Cycling cultures, culture and cycling

This is the author's final accepted version, pre-proof reading of a book chapter published by University of Chester Press, 2015. Included with kind permission of University of Chester Press.Summary of the book Cycling cultures edited by Peter Cox (2015)

Sensory ethnography and the cycling body: Challenges of research and communication

Recent interest in sensory ethnography has challenged ethnographers to extend their attention beyond the visual and into the full sensory world. This paper reports on the experiences of a six-month research project exploring the sensory world of cycle users in and around Munich. It explores two contrasting but complimentary sets of urban journeys, one constrained by streetscapes, and one by greenways and urban parks. The conscious employment of a sensory studies approach assists the researcher to consider how the processes of cycling involve a whole body sensory experience. It also questions the adequacy of the western sensory five-sense construct, which is generally limited to external sensory input and lacks clear articulation of the intra-bodily senses of muscle feel, fatigues and stress. Thus, it begins to unpack the complex of elements subsumed within the general heading of kineaesthetics in recent studies of cycling and walking. Combining visual ethnography - using filmed journeying - with GPS and biometric data, (heart rates and power measurement), more commonly associated with sports training and analysis, provides a different view of the embodied journeying even at a mundane level. These ‘objective’ or ‘hard’ data measurements are also mediated through autoethnographic considerations of the subjective feelings and experiences associated with these ‘hard’ data. A conventional written paper is presented with accompanying film - incorporating data overlay - so that the story of a sample (composite) journey can narrate the findings of the research.Research enabled by a Leverhulme Trust International Academic Fellowship IAF-2014-01