96 research outputs found
TeV physics and the Planck scale
Supersymmetry is one of the best motivated possibilities for new physics at
the TeV scale. However, both concrete string constructions and phenomenological
considerations suggest the possibility that the physics at the TeV scale could
be more complicated than the Minimal Supersymmetric Standard Model (MSSM),
e.g., due to extended gauge symmetries, new vector-like supermultiplets with
non-standard SU(2)xU(1) assignments, and extended Higgs sectors. We briefly
comment on some of these possibilities, and discuss in more detail the class of
extensions of the MSSM involving an additional standard model singlet field.
The latter provides a solution to the problem, and allows significant
modifications of the MSSM in the Higgs and neutralino sectors, with important
consequences for collider physics, cold dark matter, and electroweak
baryogenesis.Comment: 17 pages, 5 figures. To appear in New Journal of Physic
Beyond the âTomlinson Trapâ: analysing the effectiveness of section 1 of the Compensation Act 2006
One of the intentions underpinning section 1 of the Compensation Act 2006 was to provide reassurance to individual volunteers, and voluntary organisations, involved in what the provision called âdesirable activitiesâ and including sport. The perception was that such volunteers, motivated by an apprehension about their increased vulnerability to negligence liability, and as driven by a fear of a wider societal compensation culture, were engaging excessively in risk-averse behaviour to the detriment of such socially desirable activities. Academic commentary on section 1 of the Compensation Act 2006 has largely regarded the provision as unnecessary and doing little more than restating existing common law practice. This article argues otherwise and, on critically reviewing the emerging jurisprudence, posits the alternative view that section 1, in practice, affords an enhanced level of protection and safeguarding for individuals undertaking functions in connection with a desirable activity. Nonetheless, the occasionally idiosyncratic judicial interpretation given to term âdesirable activityâ, potentially compounded by recent enactment of the Social Action, Responsibility and Heroism Act 2015, remains problematic. Two points of interest will be used to inform this debate. First, an analysis of the then House of Lordsâ decision in Tomlinson and its celebrated âbalancing exerciseâ when assessing reasonableness in the context of negligence liability. Second, a fuller analysis of the application of section 1 in the specific context of negligence actions relating to the coaching of sport where it is argued that the, albeit limited, jurisprudence might support the practical utility of a heightened evidential threshold of gross negligence
Sports coaching and the law of negligence: implications for coaching practice
The ordinary principles of the law of negligence are applicable in the context of sport, including claims brought against volunteer and professional coaches. Adopting the perspective of the coach, this article intends to raise awareness of the emerging intersection between the law of negligence and sports coaching, by utilising an interdisciplinary analysis designed to better safeguard and reassure coaches mindful of legal liability. Detailed scrutiny of two cases concerning alleged negligent coaching, with complementary discussion of some of the ethical dilemmas facing modern coaches, reinforces the legal duty and obligation of all coaches to adopt objectively reasonable and justifiable coaching practices when interacting with athletes. Problematically, since research suggests that some coaching practice may be underpinned by âentrenched legitimacyâ and âuncritical inertiaâ, it is argued that coach education and training should place a greater emphasis on developing a coachâs awareness and understanding of the evolving legal context in which they discharge the duty of care incumbent upon them
Methods for classically simulating noisy networked quantum architectures
As research on building scalable quantum computers advances, it is important
to be able to certify their correctness. Due to the exponential hardness of
classically simulating quantum computation, straight-forward verification
through classical simulation fails. However, we can classically simulate small
scale quantum computations and hence we are able to test that devices behave as
expected in this domain. This constitutes the first step towards obtaining
confidence in the anticipated quantum-advantage when we extend to scales which
can no longer be simulated.
Realistic devices have restrictions due to their architecture and limitations
due to physical imperfections and noise. Here we extend the usual ideal
simulations by considering those effects. We provide a general methodology for
constructing realistic simulations emulating the physical system which will
both provide a benchmark for realistic devices, and guide experimental research
in the quest for quantum-advantage.
We exemplify our methodology by simulating a networked architecture and
corresponding noise-model; in particular that of the device developed in the
Networked Quantum Information Technologies Hub (NQIT). For our simulations we
use, with suitable modification, the classical simulator of of Bravyi and
Gosset. The specific problems considered belong to the class of Instantaneous
Quantum Polynomial-time (IQP) problems, a class believed to be hard for
classical computing devices, and to be a promising candidate for the first
demonstration of quantum-advantage. We first consider a subclass of IQP,
defined by Bermejo-Vega et al, involving two-dimensional dynamical quantum
simulators, before moving to more general instances of IQP, but which are still
restricted to the architecture of NQIT.Comment: 55 pages, 16 figure
Dynamic multi-segmental postural control in patients with chronic non-specific low back pain compared to pain-free controls: A cross-sectional study
Reduced postural control is thought to contribute to the development and persistence of chronic non-specific low back pain (CNLBP). It is therefore frequently assessed in affected patients and commonly reported as the average amount of postural sway while standing upright under a variety of sensory conditions. These averaged linear outcomes, such as mean centre of pressure (CP) displacement or mean CP surface areas, may not reflect the true postural status. Adding nonlinear outcomes and multi-segmental kinematic analysis has been reported to better reflect the complexity of postural control and may detect subtler postural differences. In this cross-sectional study, a combination of linear and nonlinear postural parameters were assessed in patients with CNLBP (n = 24, 24-75 years, 9 females) and compared to symptom-free controls (CG, n = 34, 22-67 years, 11 females). Primary outcome was postural control measured by variance of joint configurations (uncontrolled manifold index, UI), confidence ellipse surface areas (CEA) and approximate entropy (ApEn) of CP dispersion during the response phase of a perturbed postural control task on a swaying platform. Secondary outcomes were segment excursions and clinical outcome correlates for pain and function. Non-parametric tests for group comparison with P-adjustment for multiple comparisons were conducted. Principal component analysis was applied to identify patterns of segmental contribution in both groups. CNLBP and CG performed similarly with respect to the primary outcomes. Comparison of joint kinematics revealed significant differences of hip (P < .001) and neck (P < .025) angular excursion, representing medium to large group effects (r's = .36 - .51). Significant (P's < .05), but moderate correlations of ApEn (r = -.42) and UI (r = -.46) with the health-related outcomes were observed. These findings lend further support to the notion that averaged linear outcomes do not suffice to describe subtle postural differences in CNLBP patients with low to moderate pain status
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