121073474
Homotopy groups and (2+1)-dimensional quantum de Sitter gravity
Abstract The integrated CCR (canonical commutation relations) for (2 + 1)-dimensional de Sitter/ anti-de Sitter gravity in first-order formalism are used to derive generalised spinor representations Ψ: π 1 (Σ) → SL (2, C )/ SL (2, R ) ⊗ SL (2, R ) of the fundamental group of the initial data surface Σ 2 . The matrix elements of Ψ ( U ), Ψ ( V ), with U ≠ V are in general non-commuting according to a set of formal rules which are related to the theory of quantum groups. The Poincare theory appears as a limiting case.
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.
126036591
Lorentz invariance and the group manifold approach
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.
117052872
Normal coordinates in canonical form
199679707
Measurement of muon plus proton final states in $\nu_{\mu}$ Interactions on Hydrocarbon at $ $ = 4.2 GeV
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.