218 research outputs found
EFFECTS OF BALANCING HAMSTRING AND QUADRICEPS MUSCLE TORQUE ON RUNNING TECHNIQUE
It has been suggested that balancing the isokinetic strength of quadriceps (Q) and hamstring (H) muscles can reduce hamstring injuries during running (Croisier et al 2008). The efficacy of this type of intervention has been previously explored. To further the knowledge of the H: Q relationship we have examined the interventionâs affect on running technique as presented here
A movement ecology toolkit : Novel biotelemetry methodologies for elucidating animal behaviour and location.
Complete Six-Gluon Disk Amplitude in Superstring Theory
We evaluate all next-to-maximal helicity violating (NMHV) six-gluon
amplitudes in type I open superstring theory in four dimensions, at the disk
level, to all orders in alpha'. Although the computation utilizes
supersymmetric Ward identities, the result holds for all compactifications,
even for those that break supersymmetry and is completely model-independent.
Together with the maximally helicity violating (MHV) amplitudes presented in
the previous work, our results provide the complete six-gluon disk amplitude.Comment: 29 pages, harvmac, v2: Appendix B3 added, v3: Final version to appear
in NP
Ancient Roman coin retrieval : a systematic examination of the effects of coin grade
Ancient coins are historical artefacts of great significance which attract the interest of scholars, and a large and growing number of amateur collectors. Computer vision based analysis and retrieval of ancient coins holds much promise in this realm, and has been the subject of an increasing amount of research. The present work is in great part motivated by the lack of systematic evaluation of the existing methods in the context of coin grade which is one of the key challenges both to humans and automatic methods. We describe a series of methods â some being adopted from previous work and others as extensions thereof â and perform the first thorough analysis to date.Postprin
Multigluon tree amplitudes with a pair of massive fermions
We consider the calculation of n-point multigluon tree amplitudes with a pair
of massive fermions in QCD. We give the explicit transformation rules of this
kind of massive fermion-pair amplitudes with respect to different reference
momenta and check the correctness of them by SUSY Ward identities. Using these
rules and onshell BCFW recursion relation, we calculate the analytic results of
several n-point multigluon amplitudes.Comment: 15page
Prying into the intimate secrets of animal lives; software beyond hardware for comprehensive annotation in âDaily Diaryâ tags
Smart tags attached to freely-roaming animals recording multiple parameters at infra-second rates are becoming commonplace, and are transforming our understanding of the way wild animals operate. However, interpretation of such data is complex and currently limits the ability of biologists to realise the value of their recorded information. This work presents a single program, FRAMEWORK 4, that uses a particular sensor constellation described in the?Daily Diary? tag (recording tri-axial acceleration, tri-axial magnetic field intensity, pressure and e.g. temperature and light intensity) to determine the 4 key elements considered pivotal within the conception of the tag. These are; animal trajectory, behaviour, energy expenditure and quantification of the environment in which the animal operates. The program takes the original data recorded by the Daily Dairy and transforms it into dead-reckoned movements,template-matched behaviours, dynamic body acceleration-derived energetics and positionlinked environmental data before outputting it all into a single file. Biologists are thus left with a single data set where animal actions and environmental conditions can be linked across time and space.Fil: Walker, James S.. Swansea University. College Of Sciences; Reino UnidoFil: Jones, Mark W.. Swansea University. College Of Sciences; Reino UnidoFil: Laramee, Robert S.. Swansea University. College Of Sciences; Reino UnidoFil: Holton, Mark D.. Swansea University; Reino UnidoFil: Shepard, Emily L. C.. Swansea University. College Of Sciences; Reino UnidoFil: Williams, Hannah J.. Swansea University. College Of Sciences; Reino UnidoFil: Scantlebury, D. Michael. The Queens University Of Belfast; IrlandaFil: Marks, Nikki, J.. The Queens University Of Belfast; IrlandaFil: Magowan, Elizabeth A.. The Queens University Of Belfast; IrlandaFil: Maguire, Iain E.. The Queens University Of Belfast; IrlandaFil: Grundy, Ed. Swansea University. College Of Sciences; Reino UnidoFil: Di Virgilio, Agustina Soledad. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Patagonia Norte. Instituto de InvestigaciĂłn En Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue; ArgentinaFil: Wilson, Rory P.. Swansea University. College Of Sciences; Reino Unid
MHV-Vertices for Gravity Amplitudes
We obtain a CSW-style formalism for calculating graviton scattering
amplitudes and prove its validity through the use of a special type of
BCFW-like parameter shift. The procedure is illustrated with explicit examples.Comment: 21 pages, minor typos corrected, proof added in section
Orbifolding the Twistor String
The D-instanton expansion of the topological B-model on the supermanifold
CP(3|4) reproduces the perturbative expansion of N=4 Super Yang-Mills theory.
In this paper we consider orbifolds in the fermionic directions of CP(3|4).
This operation breaks the SU(4) R-symmetry group, reducing the amount of
supersymmetry of the gauge theory. As specific examples we take N=1 and N=2
orbifolds and obtain the corresponding superconformal quiver theories. We
discuss the D1 instanton expansion in this context and explicitly compute some
amplitudes.Comment: 24 pages, 8 figures; v2: minor correction
Proof of the MHV vertex expansion for all tree amplitudes in N=4 SYM theory
We prove the MHV vertex expansion for all tree amplitudes of N=4 SYM theory.
The proof uses a shift acting on all external momenta, and we show that every
N^kMHV tree amplitude falls off as 1/z^k, or faster, for large z under this
shift. The MHV vertex expansion allows us to derive compact and efficient
generating functions for all N^kMHV tree amplitudes of the theory. We also
derive an improved form of the anti-NMHV generating function. The proof leads
to a curious set of sum rules for the diagrams of the MHV vertex expansion.Comment: 40 pages, 7 figure
Recursive Calculation of One-Loop QCD Integral Coefficients
We present a new procedure using on-shell recursion to determine coefficients
of integral functions appearing in one-loop scattering amplitudes of gauge
theories, including QCD. With this procedure, coefficients of integrals,
including bubbles and triangles, can be determined without resorting to
integration. We give criteria for avoiding spurious singularities and boundary
terms that would invalidate the recursion. As an example where the criteria are
satisfied, we obtain all cut-constructible contributions to the one-loop
n-gluon scattering amplitude, A_n^{oneloop}(...--+++...), with split-helicity
from an N=1 chiral multiplet and from a complex scalar. Using the
supersymmetric decomposition, these are ingredients in the construction of QCD
amplitudes with the same helicities. This method requires prior knowledge of
amplitudes with sufficiently large numbers of legs as input. In many cases,
these are already known in compact forms from the unitarity method.Comment: 36 pages; v2 clarification added and typos fixed, v3 typos fixe
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