19,682 research outputs found
Anomalies, boundaries and the in-in formalism
In the context of quantum field theory, an anomaly exists when a theory has a
classical symmetry which is not a symmetry of the quantum theory. This short
exposition aims at introducing a new point of view, which is that the proper
setting for anomaly calculations is the `in-in', or closed-time path
formulation of quantum field theory. There are also some new results for
anomalies in the context of boundary value problems, and a new correction to
the heat-kernel coefficient.Comment: 11 page
Review of beryllium technology for spacecraft applications
Joining, working, and structural properties of beryllium and beryllium alloys for spacecraft application
Inductive benchmarking for purely functional data structures
Every designer of a new data structure wants to know how well it performs in comparison with others. But finding, coding and testing applications as benchmarks can be tedious and time-consuming. Besides, how a benchmark uses a data structure may considerably affect its apparent efficiency, so the choice of applications may bias the results. We address these problems by developing a tool for inductive benchmarking. This tool, Auburn, can generate benchmarks across a wide distribution of uses. We precisely define 'the use of a data structure', upon which we build the core algorithms of Auburn: how to generate a benchmark from a description of use, and how to extract a description of use from an application. We then apply inductive classification techniques to obtain decision trees for the choice between competing data structures. We test Auburn by benchmarking several implementations of three common data structures: queues, random-access lists and heaps. These and other results show Auburn to be a useful and accurate tool, but they also reveal some limitations of the approach
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