119470781
Some Applications of the ADM Formalism
The ADM Formalism is discussed in the context of 2+1--dimensional gravity, uniting two areas of relativity theory in which Stanley Deser has been particularly active. For spacetimes with topology R x T^2 the partially reduced and fully reduced ADM formalism are related and quantized, and the role of "large diffeomorphisms" (the modular group) in the quantum theory is illustrated.
5325226
A QUANTUM GOLDMAN BRACKET FOR LOOPS ON SURFACES
In the context of (2+1)–dimensional gravity, we use holonomies of constant connections which generate a q–deformed representation of the fundamental group to derive signed area phases which relate the quantum matrices assigned to homotopic loops. We use these features to determine a quantum Goldman bracket (commutator) for intersecting loops on surfaces, and discuss the resulting quantum geometry.
126036591
Lorentz invariance and the group manifold approach
117052872
Normal coordinates in canonical form
124467838
Lorentz Invariance in tangent space
122698975
GROUP MANIFOLD DERIVATION OF CANONICAL THEORIES
The covariant canonical formalism previously developed supplemented by gauge fixing conditions leads naturally to corresponding component theories. We illustrate the method by deriving the “new variables” theory of Ashtekar, and the standard canonical tetrad theory. The method does not use the spinor formalism.
120224392
The effects of neutron irradiation on multi-pixel hybrid photodiode tubes
Abstract The effects of neutron irradiation on a multi-pixel hybrid photodiode tube (HPD) were studied. The HPD underwent an integrated fluence of 10 13 neutrons cm 2 from a 252 Cf source. Increased leakage currents were observed during this irradiation, consistent with that observed from bare silicon detectors. The HPD was observed to be fully operational, with acceptable leakage currents, at the fluences expected during the lifetime of the CMS experiment. After the full dosage, small intrapixel inhomogeneities were observed in the HPD's response. The origins of these inhomogeneities and methods to mitigate the radiation damage were investigated.
122041574
Multi-pixel hybrid photodiode tubes for the CMS hadron calorimeter
Abstract Avalanche Photodiodes and 7-channel HPDs from DEP were installed on a prototype CMS HCAL and their response to muons, electrons and pions was measured in a test beam. DC response to a radioactive source used to calibrate the tiles was also studied. Increase in leakage current in the HPD from an integrated dose of 10 13 neutrons/cm 2 was observed using a Cf source.