On the wrapping correction to single magnon energy in twisted N=4 SYM

We apply Zeilberger summation to derive a closed formula for the wrapping correction to one-impurity states in the su(2) sector of the beta-deformed N=4 SYM theory at beta=1/2. As an application depending heavily on the result, we compute the large volume expansion of the wrapping correction.Comment: 15 page

Study of dynamical supersymmetry breaking for the two dimensional lattice Wess-Zumino model

A new approach to the study of the transition point in a class of two dimensional Wess-Zumino models is presented. The method is based on the calculation of rigorous lower bounds on the ground state energy density in the infinite lattice limit. Such bounds are useful in the discussion of supersymmetry phase transition. The transition point is then determined and compared with recent results based on large-scale Green Function Monte Carlo simulations with good agreement.Comment: 4 pages, 1 figure, Talk presented at Quark Confinement and the Hadron Spectrum VI, Villasimius, Sardinia, Italy, September 21-25, 200

Dynamical supersymmetry breaking and phase diagram of the lattice Wess-Zumino model

We study dynamical supersymmetry breaking and the transition point by non-perturbative lattice techniques in a class of two-dimensional N=1 Wess-Zumino model. The method is based on the calculation of rigorous lower bounds on the ground state energy density in the infinite-lattice limit. Such bounds are useful in the discussion of supersymmetry phase transition. The transition point is determined with this method and then compared with recent results based on large-scale Green Function Monte Carlo simulations with good agreement.Comment: 6 pages, 4 figs. Lattice2005 (theory), uses Po

Evolution of fermionic systems as an expectation over Poisson processes

We derive an exact probabilistic representation for the evolution of a Hubbard model with site- and spin-dependent hopping coefficients and site-dependent interactions in terms of an associated stochastic dynamics of a collection of Poisson processes.Comment: 4 pages, contribution to the proceedings of tenth International Conference on Recent Progress in Many-Body Theories, Seattle, 199

Highest states in light-cone AdS5×S5AdS_5\times S^5 superstring

We study the highest states in the compact rank-1 sectors of the AdS5 X S5 superstring in the framework of the recently proposed light cone Bethe Ansatz equations. In the su(1|1) sector we present strong coupling expansions in the two limits L,lambda -> OO (expanding in power of lambda^{-1/4} with fixed large L) and lambda, L -> OO (expanding in power of 1/L with fixed large lambda) where lambda is the 't Hooft coupling and L is the number of Bethe momenta. The two limits do not commute apart from the leading term which reproduces the result obtained with the Arutyunov-Frolov-Staudacher phase in the lambda, L -> OO limit. In the su(2) sector we perform the strong coupling expansions in the L->OO limit up to O(lambda^{-1/4}), and our result is in agreement with previuos String Bethe Ansatz analysis.Comment: 33 pages, 3 eps figure

Phase diagram of the lattice Wess-Zumino model from rigorous lower bounds on the energy

We study the lattice N=1 Wess-Zumino model in two dimensions and we construct a sequence $\rho^{(L)}$ of exact lower bounds on its ground state energy density $\rho$, converging to $\rho$ in the limit $L\to\infty$. The bounds $\rho^{(L)}$ can be computed numerically on a finite lattice with $L$ sites and can be exploited to discuss dynamical symmetry breaking. The transition point is determined and compared with recent results based on large-scale Green Function Monte Carlo simulations with good agreement.Comment: 32 pages, 12 figure

The scaling function at strong coupling from the quantum string Bethe equations

We study at strong coupling the scaling function describing the large spin anomalous dimension of twist two operators in ${\cal N}=4$ super Yang-Mills theory. In the spirit of AdS/CFT duality, it is possible to extract it from the string Bethe Ansatz equations in the $\mathfrak{sl}(2)$ sector of the \ads superstring. To this aim, we present a detailed analysis of the Bethe equations by numerical and analytical methods. We recover several short string semiclassical results as a check. In the more difficult case of the long string limit providing the scaling function, we analyze the strong coupling version of the Eden-Staudacher equation, including the Arutyunov-Frolov-Staudacher phase. We prove that it admits a unique solution, at least in perturbation theory, leading to the correct prediction consistent with semiclassical string calculations.Comment: 25 pages, 5 eps figure

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

A note on quantum-dynamical symmetries.

We consider the problem of finding, for a given quantum system, a compact Lie group of symmetries such that to any energy level there corresponds an irreducible representation of the group. It is concluded that this is not possible except for particular cases, and that, in general, to a given energy level there corresponds a reducible representation of the group. Examples with such a behaviour are given. Si considera il problema di trovare, per un sistema quantistico dato, un compatto gruppo di Lie di simmetrie, tale che ad ogni livello di energia corrisponda una rappresentazione irriducibile del gruppo. Si conclude che ciò non è possibile salvo che in particolari casi, e che, in generale, ad un livello di energia data corrisponde una rappresentazione riducibile del gruppo. Si danno esempi di tale fenomeno. Мы рассматриваем проблему нахождения для данной квантовой системы компактной группы Ли таких симметрий, что любому уровню знергии соответствует неприводимое представление зтой группы. Утверждается, что зто невоэможно, эа исключением частных случаев, и что, в обшем случае, эаданному уровню знергии соответствует неприводимое представление группы. Приводятся примеры с таким поведением