Generalized stochastic Schroedinger equations for state vector collapse

A number of authors have proposed stochastic versions of the Schr\"odinger equation, either as effective evolution equations for open quantum systems or as alternative theories with an intrinsic collapse mechanism. We discuss here two directions for generalization of these equations. First, we study a general class of norm preserving stochastic evolution equations, and show that even after making several specializations, there is an infinity of possible stochastic Schr\"odinger equations for which state vector collapse is provable. Second, we explore the problem of formulating a relativistic stochastic Schr\"odinger equation, using a manifestly covariant equation for a quantum field system based on the interaction picture of Tomonaga and Schwinger. The stochastic noise term in this equation can couple to any local scalar density that commutes with the interaction energy density, and leads to collapse onto spatially localized eigenstates. However, as found in a similar model by Pearle, the equation predicts an infinite rate of energy nonconservation proportional to $\delta^3(\vec 0)$, arising from the local double commutator in the drift term.Comment: 24 pages Plain TeX. Minor changes, some new references. To appear in Journal of Physics

Relinquishing and Governing the Volatile: The Many Afghanistans and Critical Research Agendas of NATO's Governance

This article invites academics and policy analysts to examine the mechanisms and legacy of NATO's security and development governance of Afghan social spaces by using critical theory concepts. It argues that such scholarly endeavors are growing in importance as the United States and NATO gradually pull their troops out of Afghanistan. Thus, the article suggests a broad twofold research agenda. First, it points out that researching social spaces such as towns, villages, marketplaces, and neighborhoods beyond the realm of intergovernmental politics can lead to thick descriptions of how such places have been governed from within by agents external to them. Second, the study argues for a multifaceted examination of instruments, strategies, and institutions of security governance, its conduct and social effects by deploying critical and Foucauldian concepts such as the rationality and apparatuses of power relations. Thereby, it proposes an inquiry into Provincial Reconstruction Teams and Afghan National Security Forces as spatially and temporally specific apparatuses of surveillance and security

New Loop Representations for 2+1 Gravity

Since the gauge group underlying 2+1-dimensional general relativity is non-compact, certain difficulties arise in the passage from the connection to the loop representations. It is shown that these problems can be handled by appropriately choosing the measure that features in the definition of the loop transform. Thus, ``old-fashioned'' loop representations - based on ordinary loops - do exist. In the case when the spatial topology is that of a two-torus, these can be constructed explicitly; {\it all} quantum states can be represented as functions of (homotopy classes of) loops and the scalar product and the action of the basic observables can be given directly in terms of loops.Comment: 28pp, 1 figure (postscript, compressed and uuencoded), TeX, Pennsylvania State University, CGPG-94/5-

Proceedings of a roundtable event ‘Workplace Diet and Health – priorities for researchers and practitioners’

Understanding how the work environment impacts health behaviours is essential to a life course approach in public health nutrition. A roundtable event ‘Workplace Diet and Health – priorities for researchers and practitioners’ was held by the Nutrition Society in October 2022. The overarching aims of the roundtable event were to consider (i) the relevance of nutritional wellbeing for employers and organisations, (ii) the research priorities for workplace diet and health and (iii) how researchers and practitioners can work with stakeholders in the development and testing of workplace diet and health interventions and nutritional education. Participants represented a range of stakeholders including dietetic and nutrition professionals working in workplace health, academics and science communication with an interest in workplace diet and health, non-governmental organisations and providers of workplace nutritional health and wellbeing programmes. All roundtable participants agreed that good nutrition and access to healthy food at work was part of corporate responsibility comparable to that of health and safety provision. It was recognised that nutritional wellbeing was not seen as a priority by many companies due to the complexity and wide range of employee health and wellbeing options available and the perceived lack of clear financial benefit. Three priority areas were identified and agreed upon by roundtable participants: (1) strengthening the evidence base to demonstrate the tangible benefit of nutritional wellbeing interventions in the workplace, (2) creating a knowledge exchange hub to share best practices and experiences of working across sectors and (3) expand stakeholder engagement in workplace nutritional wellbeing