Understanding Gauge
I consider two usages of the expression “gauge theory.” On one, a gauge theory is a theory with excess structure; on the other, a gauge theory is any theory appropriately related to classical electromagnetism. I make precise one sense in which one formulation of electromagnetism, the paradigmatic gauge theory on both usages, may be understood to have excess structure and then argue that gauge theories on the second usage, including Yang-Mills theory and general relativity, do not generally have excess structure in this sense.
Gauging what's real : the conceptual foundations of contemporary gauge theories
Introduction 1. What is a Gauge Theory? 2. The Aharonov-Bohm E[currency]ect 3. Classical Gauge Theories 4. Interpreting Classical Gauge Theories 5. Quantized Yang-Mills Gauge Theories 6. The Empirical Import of Gauge Symmetry 7. Loop Representations 8. Interpreting Quantized Yang-Mills Gauge Theories 9. Conclusions
AN ANALYSIS OF POLYMERIC THICK-FILM RESISTORS AS PRESSURE SENSORS
Abstract The strain-sensing characteristics of thick-film polymer-based resistors printed and cured on 96% alumina are presented. Two layout configurations have been analysed: planar and sandwich. Various strain-gauge characteristics have been studied, including the mechanical and temperature-dependent properties of the polymeric films. It has been shown that the planar polymer resistors exhibit low sensitivity, comparable to that of metal-foil gauges, whereas the MRM (metal-resistor-metal) configurations exhibit similar characteristics to those of cermet thick-film MRM gauges. It has also been observed that the mechanical properties of the polymeric films are significantly poorer than those of cermet-based gauges. This degradation in performance is attributed to the epoxy/pseudo-plastic structure of the polymeric thick-film resistor layer.