The Leigh-Strassler Deformation and the Quest for Integrability

In this paper we study the one-loop dilatation operator of the full scalar field sector of Leigh-Strassler deformed N=4 SYM theory. In particular we map it onto a spin chain and find the parameter values for which the Reshetikhin integrability criteria are fulfilled. Some years ago Roiban found an integrable subsector, consisting of two holomorphic scalar fields, corresponding to the XXZ model. He was pondering about the existence of a subsector which would form generalisation of that model to an integrable su_q(3) model. Later Berenstein and Cherkis added one more holomorphic field and showed that the subsector obtained this way cannot be integrable except for the case when q=e^{i beta}, beta real. In this work we show if we add an anti-holomorphic field to the two holomorphic ones, we get indeed an integrable su_q(3) subsector. We find it plausible that a direct generalisation to a su_q(3,2) one-loop sector will exist, and possibly beyond one-loop.Comment: 2 figures, fixed some typos, and improved the notation a bi

A hierarchy of exactly solvable spin-1/2 chains with so(N)_1 critical points

We construct a hierarchy of exactly solvable spin-1/2 chains with so(N)_1 critical points. Our construction is based on the framework of condensate-induced transitions between topological phases. We employ this framework to construct a Hamiltonian term that couples N transverse field Ising chains such that the resulting theory is critical and described by the so(N)_1 conformal field theory. By employing spin duality transformations, we then cast these spin chains for arbitrary N into translationally invariant forms that all allow exact solution by the means of a Jordan-Wigner transformation. For odd N our models generalize the phase diagram of the transverse field Ising chain, the simplest model in our hierarchy. For even N the models can be viewed as longer ranger generalizations of the XY chain, the next model in the hierarchy. We also demonstrate that our method of constructing spin chains with given critical points goes beyond exactly solvable models. Applying the same strategy to the Blume-Capel model, a spin-1 generalization of the Ising chain in a generic magnetic field, we construct another critical spin-1 chain with the predicted CFT describing the criticality.Comment: 24 pages, 5 figures; v2: minor changes and added reference

Condensate-induced transitions and critical spin chains

We show that condensate-induced transitions between two-dimensional topological phases provide a general framework to relate one-dimensional spin models at their critical points. We demonstrate this using two examples. First, we show that two well-known spin chains, namely the XY chain and the transverse field Ising chain with only next-nearest-neighbor interactions, differ at their critical points only by a non-local boundary term and can be related via an exact mapping. The boundary term constrains the set of possible boundary conditions of the transverse field Ising chain, reducing the number of primary fields in the conformal field theory that describes its critical behavior. We argue that the reduction of the field content is equivalent to the confinement of a set of primary fields, in precise analogy to the confinement of quasiparticles resulting from a condensation of a boson in a topological phase. As the second example we show that when a similar confining boundary term is applied to the XY chain with only next-nearest-neighbor interactions, the resulting system can be mapped to a local spin chain with the u(1)_2 x u(1)_2 critical behavior predicted by the condensation framework.Comment: 5 pages, 1 figure; v2: several minor textual change

Controlling SARS Related Illnesses in the Indoor Environment using HVAC Ventilation Techniques

The COVID-19 pandemic has brought on a need for better ventilation systems due to the deadly spreading of the SARS-CoV and SARS-CoV-2 illness through the air. As the positivity rate increases sharply, this study is pertinent in the fight against the virus. The implementation of MERV filters and ventilation rates while also understanding respiratory droplets and how they move through the air is an important part of understanding airborne transmission. Much research has been done on MERV filtration and respiratory droplets and their traveling methods in the air, and this research aims to find the commonalities between prior research, and to provide further insight into topic. Offices around the world have been navigating creating a safe environment for their employees to be able to work in person rather than remotely

The Experiences of a Foundation With a Limited Life: Benefits and Challenges

This article discusses the benefits and drawbacks of a limited-life foundation’s philanthropy practice. The strengths, including a sharpened strategic focus and sense of urgency, and the challenges, such as ensuring impact and dealing with grantee dependency, are also relevant when closing a program. Drawing on reflections from the director general of the MAVA Foundation and learnings from foundations that have recently closed, this article also discusses how to prepare for the end date of a limited-life foundation. MAVA, a Swiss-based grantmaking foundation for 25 years, has a planned end date of 2022. The article features key lessons for foundations considering closure, and will examine why some grantmakers should consider a limited-life model instead of operating in perpetuity

Sweden—the world´s most sustainable country: Political statements and goals for a sustainable society

Sweden, a small country with almost 10 million inhabitants, is the world’s most sustainable country according to some reports that compare environmental, social, and governance components between nations. Sweden plays a significant role in the European Union’s work for a sustainable society in the European Union. Strict environmental policies and governmental initiatives that encourage all members of the society to invest in climate change projects are among the reasons that put Sweden on top of sustainable ranking lists. During the 2015 United Nations Climate Change Conference in Paris, a number of goals were agreed upon and formalized as the Paris Agreement. One important aspect of the Paris Agreement is that there has to be collaboration between nations in the work against global warming. Sweden is already taking steps to achieve many of the goals set out in the 2015 UN Climate Conference as its government has established robust environmental policies. One such agency, Naturvårdsverket (the Swedish Environmental Protection Agency), is responsible for monitoring the state of the environment. Naturvårdsverket’s work is largely influenced by Sweden’s national environmental objectives. One generational goal, sixteen environmental quality objectives and 24 milestone targets define the direction of environmental work in Sweden, within the EU, and internationally. It is with frameworks like the national environmental objectives and governmental initiatives that encourage members of the society to actively participate in the work for climate change, that the Swedish government develops and implements its environmental policy. 

Using Mentoring Enactment Theory to Explore the Doctoral Student-Faculty Member Mentoring Relationship

The purpose of this dissertation was threefold. The first purpose was to examine the advisor-advisee mentoring relationship using Mentoring Enactment Theory (Kalbfleisch, 2002). The second purpose was to examine the relationship between advisees\u27 use of relational maintenance behaviors and their own and their advisors\u27 reports of relational characteristics (i.e., liking, communication satisfaction, relational satisfaction, trust, work commitment, and control mutuality). The third purpose was to examine the extent to which advisees\u27 relational uncertainty with their advisors was related to their use of relational maintenance behaviors and their advisors\u27 provision of career support and psychosocial support. The results of Principal Component Analyses, Pearson correlations, and MANOVAs indicate that advisors and advisees have similar perceptions of what behaviors advisees engage in to maintain their advisor-advisee mentoring relationships. These behaviors are: appreciation, courtesy (advisees only), tasks, goals, protection (advisors only), and humor. Advisees\u27 use of these relational maintenance behaviors generally is related positively their own reports of relational characteristics and received mentoring support from their advisors, but advisees\u27 use of relational maintenance behaviors is not related negatively to their relational uncertainty. Similarly, advisors\u27 reports of their advisees\u27 use of relational maintenance behaviors generally are related positively to their own reports of relational characteristics. The results indicate further that the sex composition of the advisor-advisee dyad has minimal impact on advisees\u27 use of relational maintenance behaviors and advisors\u27 provision of career support and psychosocial support for their advisees