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R. Loll 《Nuclear Physics B》1991,350(3):831-860
Starting from Rovelli-Smolin's infinite-dimensional graded Poisson-bracket algebra of loop variables, we propose a new way of constructing a corresponding quantum representation. After eliminating certain quadratic constraints, we “integrate” an infinite-dimensional subalgebra of loop variables, using a formal group law expansion. With the help of techniques from the representation theory of semidirect-product groups, we find an exact quantum representation of the full classical Poisson-bracket algebra of loop variables, without any higher-order correction terms. This opens new ways of tackling the quantum dynamics for both canonical gravity and Yang-Mills theory. 相似文献
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R. Loll 《Theoretical and Mathematical Physics》1992,93(3):1415-1432
Basic mathematical and physical concepts in loop- and path-dependent formulations of Yang-Mills theory are reviewed and set into correspondence. We point out some problems peculiar to these non-local approaches, in particular those associated with defining structure on various kinds of loop spaces. The issues of classical loop equations, differential operators, lattice gauge theory, loop algebras, and canonical quantization are discussed in some detail, and the paper concludeswith an extensive list of references.In Memory of Prof. M. C. PolivanovDepartamento de Fisica, Instituto Superior Tecnico, 1000-Lisboa, Portugal. Physics Department, Syracuse University, Syracuse, NY 13244, USA. Published in Teoreticheskaya i Matematicheskaya Fizika, Vol. 93, No. 3, pp. 481–505, December, 1992. 相似文献
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The intramolecular and long-range ferromagnetic coupling between p-phenylenediamine radical cations in head-to-tail coupled oligo(1, 4-phenyleneethynylene)s and oligo(1,4-phenylenvinylene)s between neighbors and next-nearest neighbors is described. UV/vis/near-IR experiments show that the radical cations are localized in the pendant p-phenylenediamine units of the conjugated oligomers. The ESR spectra of these oligo(1,4-phenyleneethynylene) and oligo(1, 4-phenylenvinylene) di(radical cation)s are consistent with those of a triplet state. A linear behavior is observed for the doubly integrated ESR intensity of the DeltaM(s) = +/-1 and DeltaM(s) = +/-2 signals with the inverse temperature (I approximately 1/T), consistent with Curie's law. This behavior indicates a triplet ground-state diradical with a large triplet-singlet energy gap or possibly a degeneracy of singlet and triplet states. 相似文献
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Martinez-Diaz MV Rodriguez-Morgade MS Feiters MC van Kan PJ Nolte RJ Stoddart JF Torres T 《Organic letters》2000,2(8):1057-1060
[formula: see text] New unsymmetrically substituted DB24C8-phthalocyanines, which are able to form complexes with suitable dialkylammonium cations, have been prepared. These complexes most probably have a pseudorotaxane geometry. 相似文献
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