The new urban paradigm

This paper argues in favor of a new urban model that harnesses the power that cities have to curb global warming. Such a model tackles fundamental management challenges in the energy, building and transport sectors to promote the growth of diverse and compact cities. Such a model is essential for meeting complex challenges in cities, such as promoting a cohesive social life and a competitive economic base while simultaneously preserving agricultural and natural systems crucial to soil, energy, and material resources. With most of the population living in urban areas, the G20 should recognize the key role that cities play in addressing global challenges such as climate change. Improved measures taken by cities should be an indispensable solution. The G20 Development Working Group, Climate Sustainability Working Group, and Energy Transitions Working Group should incorporate an urban approach to discussions related to climate change.Fil: Lanfranchi, Gabriel. Centro de Implementación de Políticas Públicas para la Equidad y el Crecimiento; ArgentinaFil: Herrero, Ana Carolina. Centro de Implementación de Políticas Públicas para la Equidad y el Crecimiento; ArgentinaFil: Rueda Palenzuela, Salvador. Agencia Ecología Urbana Barcelona; EspañaFil: Camilloni, Ines Angela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmósfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmósfera; ArgentinaFil: Bauer, Steffen. German Development Institute; Alemani

Improving global governance: making global institutions fit-for-purpose in 21st century

In this lecture I will: • comment on some of the complex challenges of the 21st century which cry out for effective global governance reflecting today’s geopolitical and other realities; and • examine whether global governance institutions – particularly in the areas of peace and security, economic governance, sustainable development and climate change – have kept up with geopolitical changes and been able to tackle emerging challenges to ensure their continued effectiveness, legitimacy and accountability. My working definition of global governance will be that of Lawrence Finkelstein, former professor of political science at Northern Illinois University and former vice-president of the Carnegie Endowment for International Peace. Writing in the first issue of the journal Global Governance, he suggested that global governance could be defined as ‘governing, without sovereign authority, relationships that transcend national frontiers. Global governance is doing internationally what governments do at home’ (Finkelstein, 1995). • The Rt Hon Helen Clark is presently the Administrator of the United Nations Development Programme. This is the text of an address she gave to the Institute for Governance and Policy Studies, Tuesday 13 November 2012, and is now available in Policy Quarterly – Volume 9, Issue 1 – February 201

Civil Society Challenged: Towards an Enabling Policy Environment

The roles of non-governmental or civil society organizations have become more complex, especially in the context of changing relationships with nation states and the international community. In many instances, state–civil society relations have worsened, leading experts to speak of a "shrinking space" for civil society nationally as well as internationally. The author proposes to initiate a process for the establishment of an independent high-level commission of eminent persons (i) to examine the changing policy environment for civil society organizations in many countries as well as internationally, (ii) to review the reasons behind the shrinking space civil society encounters in some parts of the world and its steady development in others, and (iii) to make concrete proposals for how the state and the international system on the one hand and civil society on the other hand can relate in productive ways in national and multilateral contexts

Sudden interaction quench in the quantum sine-Gordon model

We study a sudden interaction quench in the weak-coupling regime of the quantum sine-Gordon model. The real time dynamics of the bosonic mode occupation numbers is calculated using the flow equation method. While we cannot prove results for the asymptotic long time limit, we can establish the existence of an extended regime in time where the mode occupation numbers relax to twice their equilibrium values. This factor two indicates a non-equilibrium distribution and is a universal feature of weak interaction quenches. The weak-coupling quantum sine-Gordon model therefore turns out to be on the borderline between thermalization and non-thermalization.Comment: 18 pages, 4 figures, published in New Journal of Physic

Hadron mass scaling near the s-wave threshold

The influence of a two-hadron threshold is studied for the hadron mass scaling with respect to some quantum chromodynamics parameters. A quantum mechanical model is introduced to describe the system with a one-body bare state coupled with a single elastic two-body scattering. The general behavior of the energy of the bound and resonance state near the two-body threshold for a local potential is derived from the expansion of the Jost function around the threshold. It is shown that the same scaling holds for the nonlocal potential induced by the coupling to a bare state. In p or higher partial waves, the scaling law of the stable bound state continues across the threshold describing the real part of the resonance energy. In contrast, the leading contribution of the scaling is forbidden by the nonperturbative dynamics near the s-wave threshold. As a consequence, the bound state energy is not continuously connected to the real part of the resonance energy. This universal behavior originates in the vanishing of the field renormalization constant of the zero-energy resonance in the s wave. A proof is given for the vanishing of the field renormalization constant, together with a detailed discussion.Comment: 11 pages, 4 figures. v4: Published versio

Perturbative Renormalization of Weak-Hamiltonian Four-Fermion Operators with Overlap Fermions

The renormalization of the most general dimension-six four-fermion operators without power subtractions is studied at one loop in lattice perturbation theory using overlap fermions. As expected, operators with different chirality do not mix among themselves and parity-conserving and parity-violating multiplets renormalize in the same way. The renormalization constants of unimproved and improved operators are also the same. These mixing factors are necessary to determine physical matrix elements relevant to many phenomenological applications of weak interactions. The most important are the K0-K0bar and B0-B0bar mixings in the Standard Model and beyond, the Delta I =1/2 rule and epsilon'/epsilon.Comment: Latex, 24 pages, 1 figure include