Framework Convention on Climate Change

Author Ray Pawson presents a devastating critique of the dominant approach to systematic review namely the 'meta-analytic' approach as sponsored by the Cochrane and Campbell collaborations. In its place is commended an approach that he terms 'realist synthesis'. On this vision, the real purpose of systematic review is better to understand program theory, so that policies Author Ray Pawson presents a devastating critique of the dominant approach to systematic review namely the 'meta-analytic' approach as sponsored by the Cochrane and Campbell collaborations. In its place is commended an approach that he terms 'realist synthesis'. On this vision, the real purpose of systematic review is better to understand program theory, so that policies can be properly targeted and developed to counter an ever-changing landscape of social problems. The book will be essential reading for all those who loved (or loathed) the arguments developed in Realistic Evaluation (Sage, 1997). It offers a complete blueprint for research synthesis, supported by detailed illustrations and worked examples from across the policy waterfront.

Evidence-based Policy: A Realist Perspective

We construct a cubic field theory which provides all genus amplitudes of the topological A-model for all non-compact toric Calabi-Yau threefolds. The topology of a given Feynman diagram encodes the topology of a fixed Calabi-Yau, with Schwinger parameters playing the role of Kahler classes of the threefold. We interpret this result as an operatorial computation of the amplitudes in the B-model mirror which is the quantum Kodaira-Spencer theory. The only degree of freedom of this theory is an unconventional chiral scalar on a Riemann surface. In this setup we identify the B-branes on the mirror Riemann surface as fermions related to the chiral boson by bosonization.

/pdf/the-topological-vertex-3lrad1kwkt.pdf

The Topological Vertex

We discuss systematic approaches to the classification of string/M theory vacua, and physical questions this might help us resolve. To this end, we initiate the study of ensembles of effective Lagrangians, which can be used to precisely study the predictive power of string theory, and in simple examples can lead to universality results. Using these ideas, we outline an approach to estimating the number of vacua of string/M theory which can realize the Standard Model.

https://iopscience.iop.org/article/10.1088/1126-6708/2003/05/046/pdf

The statistics of string/M theory vacua

This paper is devoted to recent progress made towards the understanding of closed bosonic and fermionic string perturbation theory, formulated in a Lorentz-covariant way on Euclidean space-time. Special emphasis is put on the fundamental role of Riemann surfaces and supersurfaces. The differential and complex geometry of their moduli space is developed as needed. New results for the superstring presented here include the supergeometric construction of amplitudes, their chiral and superholomorphic splitting and a global formulation of supermoduli space and amplitudes.

The Geometry of String Perturbation Theory

Worldsheet approaches to D-branes on supersymmetric cycles

D-branes, exceptional sheaves and quivers on Calabi-Yau manifolds: From Mukai to McKay

http://cds.cern.ch/record/446639/files/0007075.pdf

On D-branes from gauged linear sigma models

We consider Landau-Ginzburg (LG) models with boundary conditions pre- serving A-type N = 2 supersymmetry. We show the equivalence of a linear class of boundary conditions in the LG model to a particular class of boundary states in the cor- responding CFT by an explicit computation of the open-string Witten index in the LG model. We extend the linear class of boundary conditions to general non-linear bound- ary conditions and determine their consistency with A-type N = 2 supersymmetry. This enables us to provide a microscopic description of special Lagrangian submani- folds in C n due to Harvey and Lawson. We generalise this construction to the case of hypersurfaces in P n . We nd that the boundary conditions must necessarily have vanishing Poisson bracket with the combination (W () W ()), where W ( )i s the appropriate superpotential for the hypersurface. An interesting application considered is the T 3 supersymmetric cycle of the quintic in the large complex structure limit.

http://cds.cern.ch/record/432444/files/0003242.pdf

On the Landau-Ginzburg description of boundary CFTs and special Lagrangian submanifolds

We show how to compute terms in an expansion of the world-volume superpotential for fairly general D-branes on the quintic Calabi-Yau using linear sigma model techniques, and show in examples that this superpotential captures the geometry and obstruction theory of bundles and sheaves on this Calabi-Yau.

http://cds.cern.ch/record/543703/files/0203173.pdf

T. Jayaraman

Papers

Worldsheet approaches to D-branes on supersymmetric cycles

D-branes, exceptional sheaves and quivers on Calabi-Yau manifolds: From Mukai to McKay

On D-branes from gauged linear sigma models

On the Landau-Ginzburg description of boundary CFTs and special Lagrangian submanifolds

D-branes on Calabi{Yau Manifolds and Superpotentials