Manifestly Finite Perturbation Theory for the Short-Distance Expansion of Correlation Functions in the Two Dimensional Ising Model

In the spirit of classic works of Wilson on the renormalization group and operator product expansion, a new framework for the study of the theory space of euclidean quantum field theories has been introduced. This formalism is particularly useful for elucidating the structure of the short-distance expansions of the $n$-point functions of a renormalizable quantum field theory near a non-trivial fixed point. We review and apply this formalism in the study of the scaling limit of the two dimensional massive Ising model. Renormalization group analysis and operator product expansions determine all the non-analytic mass dependence of the short-distance expansion of the correlation functions. An extension of the first order variational formula to higher orders provides a manifestly finite scheme for the perturbative calculation of the operator product coefficients to any order in parameters. A perturbative expansion of the correlation functions follows. We implement this scheme for a systematic study of correlation functions involving two spin operators. We show how the necessary non-trivial integrals can be calculated. As two concrete examples we explicitly calculate the short-distance expansion of the spin-spin correlation function to third order and the spin-spin-energy density correlation function to first order in the mass. We also discuss the applicability of our results to perturbations near other non-trivial fixed points corresponding to other unitary minimal models.Comment: 38 pages with 1 figure, UCLA/93/TEP/4

FAB LAB: AN ALTERNATE MODEL OF ICT FOR DEVELOPMENT

There is a growing sense that the Digital Divide and the role of Information and Communications Technology (ICT) in international development need to be fundamentally reconceptualized. This paper presents the composition and the rationale behind the creation of a network of fabrication laboratories, FAB LABs, whose mission is to provide concrete examples that would lay the foundation for a new framework for this reconceptualization. At the heart of this idea is the belief that the most sustainable way to bring the deepest results of the digital revolution to developing communities is to enable them to participate in creating their own technological tools for finding solutions to their own problems. Each FAB LAB consists of a collection of tools for design and modeling, prototyping and fabrication, instrumentation and testing and debugging, and documentation for a wide range of applications in formal and informal education, health and environmental monitoring, as well as economic and social development

Just Making Faces? Animatronics, Children and Computation

Computation is a powerful way of knowing and exploring the world that finds its application in a broad range of human activities, from art making to mathematical modeling. Historically, this way of knowing has been taught in a canonical, top-down abstract fashion. This thesis presents a critical historical analysis of computers and computation in order to arrive at a framework for design of spaces for introducing computational concepts. Existing work is revisited before presenting a new system called CTRL_SPACE, specifically built to as an alternate method of conveying computational concepts to young children ages four to seven

Encouraging Innovation by Engineering the Learning Curve

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