9,716 research outputs found
A surprise in the amplitude/Wilson loop duality
No full textThis is the accepted version of article 'A Surprise in the Amplitude/Wilson Loop Duality', which was first archived by Cornell University Library: arXiv:1004.2855v2 [hep-th] 29 Apr 2010
WARD AND WILSON V ANDERSON—EVOLUTION OR REVOLUTION IN NATIVE TITLE LAW?
No full textThere is now a greater degree of certainty for the petroleum industry in Native Title law following the High Court’s decisions in Ward v Western Australia1 and Wilson v Anderson2. Both decisions were handed down on 8 August 2002. Ward in particular is the most significant Native Title decision in Australia since the High Court’s decision in Wik v Queensland3 in 1996. This paper presents an analysis of the issues dealt with in Ward and Wilson v Anderson with particular emphasis on the application for petroleum. The paper will also illustrate that while greater certainty flows from these decisions, it is still necessary for petroleum and resource companies to engage with Native Title groups (particularly by negotiating agreements) to enable the valid grant of titles and tenements to land subject to Native Title.</jats:p
Conformal Ward identities for Wilson loops and a test of the duality with gluon amplitudes
No full text28 pages, 5 figuresPlanar gluon amplitudes in N=4 SYM are remarkably similar to expectation values of Wilson loops made of light-like segments. We argue that the latter can be determined by making use of the conformal symmetry of the gauge theory, broken by cusp anomalies. We derive the corresponding anomalous conformal Ward identities valid to all loops and show that they uniquely fix the form of the finite part of a Wilson loop with n cusps (up to an additive constant) for n=4 and n=5 and reduce the freedom in it to a function of conformal invariants for n>=6. We also present an explicit two-loop calculation for n=5. The result confirms the form predicted by the Ward identities and exactly matches the finite part of the two-loop five-gluon planar MHV amplitude. This constitutes another non-trivial test of the Wilson loop/gluon amplitude duality
Conformal Ward identities for Wilson loops and a test of the duality with gluon amplitudes
No full text28 pages, 5 figuresPlanar gluon amplitudes in N=4 SYM are remarkably similar to expectation values of Wilson loops made of light-like segments. We argue that the latter can be determined by making use of the conformal symmetry of the gauge theory, broken by cusp anomalies. We derive the corresponding anomalous conformal Ward identities valid to all loops and show that they uniquely fix the form of the finite part of a Wilson loop with n cusps (up to an additive constant) for n=4 and n=5 and reduce the freedom in it to a function of conformal invariants for n>=6. We also present an explicit two-loop calculation for n=5. The result confirms the form predicted by the Ward identities and exactly matches the finite part of the two-loop five-gluon planar MHV amplitude. This constitutes another non-trivial test of the Wilson loop/gluon amplitude duality
Ethics and the Social Sciences. Edited by Leo R. Ward. Contributors : Fr. G. Wilson, K. E. Boulding, Chr. Dawson, D. Bidney, H. Johnston, J. R. Brown
No full textMertens C. Ethics and the Social Sciences. Edited by Leo R. Ward. Contributors : Fr. G. Wilson, K. E. Boulding, Chr. Dawson, D. Bidney, H. Johnston, J. R. Brown. In: Revue Philosophique de Louvain. Troisième série, tome 60, n°67, 1962. pp. 478-479
Implementing large-scale quality improvement – lessons from the productive ward: Releasing time to care
No full textPurpose: This paper is concerned with facilitating large-scale quality improvement in health care, and specifically understanding more about the known challenges associated with implementation of Lean innovations: receptivity, the complexity of adoption processes, evidence of the innovation, and embedding change. Lessons are drawn from the implementation of The Productive Ward: Releasing Time to CareTM programme in English hospitals.Design/participants: The study which the paper draws upon was a mixed-method evaluation which aimed to capture the perceptions of three main stakeholder groups: national-level policymakers (15 semi-structured interviews), senior hospital managers (a national web-based survey of 150 staff), and healthcare practitioners (case studies within five hospitals involving 58 members of staff). The views of these stakeholder groups were analysed using a diffusion of innovations theoretical framework to examine aspects of the innovation, the organisation, the wider context and linkages. Findings: Although The Productive Ward was widely supported, stakeholders at different levels identified varying facilitators and challenges to implementation. Key issues for all stakeholders were staff time to work on the programme and showing evidence of the impact on staff, patients and ward environments. Implications: To support implementation policymakers should focus on expressing what can be gained locally using success stories and guidance from ‘early adopters’. Service managers, clinical educators and professional bodies can help to spread good practice and encourage professional leadership and support. Further research could help to secure support for the programme by generating evidence about the innovation, and specifically its clinical effectiveness and broader links to public expectations and experiences of healthcare.Originality/value: This paper draws lessons from the implementation of The Productive Ward programme in England which can inform the implementation of other large-scale programmes of quality improvement in health care
On perturbative scattering amplitudes in maximally supersymmetric theories
No full textPhDThere has been substantial calculational progress in the last few years in maximally
supersymmetric theories, revealing unexpected simplicity, new structures and symmetries.
In this thesis, after reviewing some of the recent advances in N = 4 super
Yang-Mills and N = 8 supergravity, we present calculations of perturbative scattering
amplitudes and polygonal lightlike Wilson loops that lead to interesting new
results.
In N = 8 supergravity, we use supersymmetric generalised unitarity to calculate
supercoe cients of box functions in the expansion of scattering amplitudes at one
loop. Recent advances have presented tree-level amplitudes in N = 8 supergravity
in terms of sums of terms containing squares of colour-ordered Yang-Mills superamplitudes.
We develop the consequences of these results for the structure of one-loop
supercoe cients, recasting them as sums of squares of N = 4 Yang-Mills expressions
with certain coe cients inherited from the tree-level superamplitudes. This
provides new expressions for all one-loop box coe cients in N = 8 supergravity,
which we check against known results in a number of cases.
In N = 4 super Yang-Mills, we focus our attention on one of the many remarkable
features of MHV scattering amplitudes, their conjectured duality to lightlike
polygon Wilson loops, which is expected to hold to all orders in perturbation theory.
This duality is usually expressed in terms of purely four-dimensional quantities
obtained by appropriate subtraction of the infrared and ultraviolet divergences from
amplitudes and Wilson loops respectively. By explicit calculation, we demonstrate
the completely unanticipated fact that the equality continues to hold at two loops
through O( ) in dimensional regularisation for both the four-particle amplitude and
the (parity-even part of the) ve-particle amplitude
Letter re: Temple to Civilization
No full textLetter from Duren J. H. Ward, author and lecturer, to the Will Rogers Committee on Memorials regarding the establishment of a Temple to Civilization in honor of Will Rogers. Enclosed is a program promoting the Temple
The Supersymmetric Ward identities on the lattice
No full textSupersymmetric (SUSY) Ward identities are considered for the N=1 SU(2) SUSY Yang Mills theory discretized on the lattice with Wilson fermions (gluinos). They are used in order to compute non-perturbatively a subtracted gluino mass and the mixing coefficient of the SUSY current. The computations were performed at gauge coupling =2.3 and hopping parameter =0.1925, 0.194, 0.1955 using the two-step multi-bosonic dynamical-fermion algorithm. Our results are consistent with a scenario where the Ward identities are satisfied up to O(a) effects. The vanishing of the gluino mass occurs at a value of the hopping parameter which is not fully consistent with the estimate based on the chiral phase transition. This suggests that, although SUSY restoration appears to occur close to the continuum limit of the lattice theory, the results are still affected by significant systematic effects
K0-K0bar mixing with Wilson fermions without subtractions
No full textBy using suitable Ward identities, we show that it is possible to compute K0-K0bar mixing without subtracting the terms generated by explicit chiral symmetry breaking present in Wilson-like lattice actions. The accuracy in the determination of the amplitudes is of O(a), which is the best one attainable in the absence of improvement
- …
