Unitary null energy condition violation in P(X)P(X) cosmologies

A non-singular cosmological bounce in the Einstein frame can only take place if the Null Energy Condition (NEC) is violated. We explore situations where a single scalar field drives the NEC violation and derive the constraints imposed by demanding tree level unitarity on a cosmological background. We then focus on the explicit constraints that arise in P(X) theories and show that constraints from perturbative unitarity make it impossible for the NEC violation to occur within the region of validity of the effective field theory without also involving irrelevant operators that arise at a higher scale that would enter from integrating out more massive degrees of freedom. Within the context of P(X) theories we show that including such operators allows for a bounce that does not manifestly violate tree level unitarity, but at the price of either imposing a shift symmetry or involving technically unnatural small operator coefficients within the low-energy effective field theory.Comment: 35 pages, 1 figur

Book Review: Local Government in a Global World: Australia and Canada in Comparative Perspective

This book compares reform trends in Australia and Canada’s local government systems over the past two decades, with attention to the impact of globalization on local governments, their bureaucracies, and local democratic accountability. Local governments in Australia and Canada show striking resemblances in relation to history, development, and contemporary issues. This reflects that in both countries, local governments remain an instrument of the states and provinces.The exploration of the connections between globalization and local government is timely given the importance of international influences on the economic, social and environmental challenges facing governments. For the local governments discussed in the book, and for many others, economic and fiscal constraints have reduced the sector's ability to meet community expectations while also responding to growing competitiveness across jurisdictions. These pressures have highlighted the benefits of encouraging regional and local differentiation, and giving prominence to ‘place’ in policy and management designs and practices

Local government funding: facing the issues

Designing funding policies to serve all the local and regional councils in New Zealand is challenging. This article looks at some of the issues that arise, and some principles for addressing funding arrangements and for considering whether current local government funding arrangements are suited to the requirements of local governments throughout New Zealand. The need for new sources of revenue for local governments in New Zealand is a topic which is raised in most reviews of local government funding. The larger question is whether the nature, level and mix of current funding sources meets the needs of all the councils, given the diversity of their roles, funding requirements, opportunities and constraints.&nbsp

Roots and tubers for the 21st century: trends, projections and policy options

"...The assessment of past trends, future prospects, and policy options reported here stems from the tradition of joint studies of roots and tubers in developing countries by the Consultative Group on International Agricultural Research (CGIAR). This report builds on that previous collaboration and represents the first intercenter effort to produce future projections of demand and supply for these crops and represents the empirical foundation of a broader effort aimed at documenting not just trends and projections but also describing research activities and organizations with the overall objective of providing a vision for research on roots and tubers in the CGIAR. Gregory J. Scott, Mark W. Rosegrant, and Claudia Ringler have synthesized a significant amount of data and information on roots and tubers in order to provide a clearer vision of their past, present,a nd future roles in the food systems of developing countries. How the production and use of these commodities have changed and will continue to change over time are all the more important to understand because of the contribution they make to the diets and income-generating activities of the rural and urban poor in Asia, Africa, and Latin America. This paper provides a fuller understanding of the prospects of roots and tubers for food, feed, and other uses in developing countries in the decades ahead. " (excerpted from Forward by Per Pinstrup-Andersen and Hubert Zandstra)Tubers Economic aspects Developing countries., Root-crops Economic aspects Developing countries., Agricultural economics and policies., Food supply Developing countries Forecasting., Assessment,

Massive Galileon Positivity Bounds

The EFT coefficients in any gapped, scalar, Lorentz invariant field theory must satisfy positivity requirements if there is to exist a local, analytic Wilsonian UV completion. We apply these bounds to the tree level scattering amplitudes for a massive Galileon. The addition of a mass term, which does not spoil the non-renormalization theorem of the Galileon and preserves the Galileon symmetry at loop level, is necessary to satisfy the lowest order positivity bound. We further show that a careful choice of successively higher derivative corrections are necessary to satisfy the higher order positivity bounds. There is then no obstruction to a local UV completion from considerations of tree level 2-to-2 scattering alone. To demonstrate this we give an explicit example of such a UV completion.Comment: 31 page

The Founding of an Urban Charter School: Three Years of Academic Growth and Key School Characteristics

The Kauffman School is a public charter school that serves students from low-income neighborhoods in Kansas City, Missouri. This paper used a matched comparison group design to estimate the impacts of the Kauffman School on student achievement, attendance, and suspensions. We found that the Kauffman School had positive and statistically significant impacts on student achievement in mathematics, reading, and science. This paper also used surveys, interviews, focus groups, and classroom observations to describe the hallmarks and operations of the Kauffman School and explore possible mechanisms for its effects, informing the literature on school effectiveness. We found evidence that the Kauffman School's hallmarks are largely being implemented faithfully, and that key stakeholders believe the Kauffman School's methods are having a positive influence on students' behavior, attitudes, and performance

Positivity Bounds for Scalar Theories

Assuming the existence of a local, analytic, unitary UV completion in a Poincar\'{e} invariant scalar field theory with a mass gap, we derive an infinite number of positivity requirements using the known properties of the amplitude at and away from the forward scattering limit. These take the form of bounds on combinations of the pole subtracted scattering amplitude and its derivatives. In turn, these positivity requirements act as constraints on the operator coefficients in the low energy effective theory. For certain theories these constraints can be used to place an upper bound on the mass of the next lightest state that must lie beyond the low energy effective theory if such a UV completion is to ever exist.Comment: 5 page