On the Schwinger-Dyson Equations for a Vertex Model Coupled to 2D Gravity

We consider a two matrix model with gaussian interaction involving the term $tr ABAB$, which is quartic in angular variables. It describes a vertex model (in particular case - of F-model type) on the lattice of fluctuating geometry and is the simplest representative of the class of matrix models describing coupling to two-dimensional gravity of general vertex models. This class includes most of physically interesting matrix models, such as lattice gauge theories and matrix models describing extrinsic curvature strings. We show that the system of loop (Schwinger-Dyson) equations of the model decouples in the planar limit and allows one to find closed equations for arbitrary correlators, including the ones involving angular variables. This provides a solution of the model in the planar limit. We write down the equations for the two-point function and the eigenvalue density and sketch the calculation of perturbative corrections to the free case.Comment: KL-TH-94/16 (a misspelled name is corrected

Market Perspectives for Products from Future Energy-Driven Biorefineries by 2020

Produced within the framework of the JRC Biofuel Thematic Programme, this study aims to identify promising market opportunities and penetration strategies for products from future energy-oriented biorefineries in Europe by 2020. In view of the immature status of energy biorefinery technologies and concepts, the analysis mostly sketches qualitative perspectives, but it does not make detailed quantitative projections. Since currently considered energy biorefineries concentrate on bioethanol-side streams, the focus of the analysis is on ethanol-related technologies, pathways and products.JRC.F.7-Energy systems evaluatio

The Future of Coal

The study aims to estimate the supply prospects for coal by 2030 and beyond as a function of likely demand. The goal of the study is not to project future coal demand, supply and prices, but rather to highlight some facts and trends that may seriously affect coal supply in the future. The analysis is based on a critical review of a number of literature sources, complemented by the author's analysis.JRC.F.2-Cleaner energie

Impacts of the Increasing Automotive Diesel Consumption in the EU.

Abstract not availableJRC.F-Institute for Energy (Petten

Shale gas for Europe – main environmental and social considerations

The purpose of this study is to provide an overview of shale gas development in the USA and to assess the implications of findings with regard to the prospects for shale gas development in the EU by 2020-2030. Particular emphasis is placed on the environmental and social aspects of market-scale extraction of shale gas. Any purely technological, techno-economic and regulatory aspects of shale gas exploitation are beyond the scope of this study. Other European Commission services, such as DG for Energy (ENER), DG for the Environment (ENV), DG for Climate Action (CLIMA), and the Joint Research Centre itself have already performed or are currently undertaking in-depth analyses of those aspects of shale gas. The analysis is based on a critical review of a number of literature sources, complemented by the authors’ analysis.JRC.H.8-Sustainability Assessmen

Bioheat Applications in the European Union. An Analysis and Perspective for 2010

Abstract not availableJRC.F-Institute for Energy (Petten

Dynamical Domain Wall Defects in 2+1 Dimensions

We study some dynamical properties of a Dirac field in 2+1 dimensions with spacetime dependent domain wall defects. We show that the Callan and Harvey mechanism applies even to the case of defects of arbitrary shape, and in a general state of motion. The resulting chiral zero modes are localized on the worldsheet of the defect, an embedded curved two dimensional manifold. The dynamics of these zero modes is governed by the corresponding induced metric and spin connection. Using known results about determinants and anomalies for fermions on surfaces embedded in higher dimensional spacetimes, we show that the chiral anomaly for this two dimensional theory is responsible for the generation of a current along the defect. We derive the general expression for such a current in terms of the geometry of the defect, and show that it may be interpreted as due to an "inertial" electric field, which can be expressed entirely in terms of the spacetime curvature of the defects. We discuss the application of this framework to fermionic systems with defects in condensed matter.Comment: 12 pages, Late

Liquefied Natural Gas for Europe - Some Important Issues for Consideration

The delivery of liquefied natural gas (LNG) from various suppliers by sea, as an alternative to pipeline shipments and supplies, is seen as a way to secure and diversify natural gas imports in the EU. The purpose of this study is to investigate four main issues that may have a significant impact on future patterns of LNG supply and demand in the EU by 2020-2030. These four issues are: 1) Security, diversity and affordability of natural gas supply; 2) Energy efficiency and greenhouse gas emissions; 3) LNG quality and 4) Shipping of LNG.JRC.F.7-Energy systems evaluatio

Abelian Vectors and Self-Dual Tensors in Six-Dimensional Supergravity

In this note we describe the most general coupling of {\it abelian} vector and tensor multiplets to six-dimensional $(1,0)$ supergravity. As was recently pointed out, it is of interest to consider more general Chern-Simons couplings to abelian vectors of the type $H^{r}=d B^{r}-1/2 c^{rab} A^{a}d A^{b}$, with $c^{r}$ matrices that may not be simultaneously diagonalized. We show that these couplings can be related to Green-Schwarz terms of the form $B^r c_r^{ab} F^a F^b$, and how the complete local Lagrangian, that embodies factorized gauge and supersymmetry anomalies (to be disposed of by fermion loops) is uniquely determined by Wess-Zumino consistency conditions, aside from an arbitrary quartic coupling for the gauginos.Comment: LaTeX file, 10 pages. Some equations, previously written with wrong notations, are correcte

A note on the 3D Ising model as a string theory

It has long been argued that the continuum limit of the 3D Ising model is equivalent to a string theory. Unfortunately, in the usual starting point for this equivalence -- a certain lattice theory of surfaces -- it is not at all obvious how to take the continuum limit. In this note, I reformulate the lattice theory of surfaces in a fashion such that the continuum limit is straightforward. I go on to discuss how this new formulation may overcome some fundamental objections to the notion that the Ising model is equivalent to a string theory. In an appendix, I also discuss some aspects of fermion doubling, and the lattice fermion formulation of the 2D Ising model.Comment: 21 pages, 11 figures. This revised manuscript is identical to the final published version (Nuclear Physics B, to appear). Aside from correcting some scattered typos, the final version corrects and expands some of the comments in the original preprint on the unoriented NSR strin