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91.
Constantin Teleman 《Inventiones Mathematicae》1998,134(1):1-57
Let G be a semi-simple group and M the moduli stack of G-bundles over a smooth, complex, projective curve. Using representation-theoretic methods, I prove the pure-dimensionality
of sheaf cohomology for certain “evaluation vector bundles” over M, twisted by powers of the fundamental line bundle. This result is used to prove a Borel-Weil-Bott theorem, conjectured by
G. Segal, for certain generalized flag varieties of loop groups. Along the way, the homotopy type of the group of algebraic
maps from an affine curve to G, and the homotopy type, the Hodge theory and the Picard group of M are described. One auxiliary result, in Appendix A, is the Alexander cohomology theorem conjectured in [Gro2]. A self-contained
account of the “uniformization theorem” of [LS] for the stack M is given, including a proof of a key result of Drinfeld and Simpson (in characteristic 0). A basic survey of the simplicial
theory of stacks is outlined in Appendix B.
Oblatum 17-XII-1996 & 26 VI-1997 相似文献
92.
E. Constantin A. Schnell F. Guidugli P. Traldi 《Journal of mass spectrometry : JMS》1992,27(3):174-178
The collision-induced decomposition pathways of phenothiazine were studied in detail by ion trap mass spectrometry. With this approach, different amounts of energy can be deposited into the fragment ions, thus favouring particular structures. Different relative abundances in the fragmentation patterns of selected ions are observed, depending on whether they are produced by electron impact or multiple mass spectrometry [(MS)n] methods. 相似文献
93.
Peter Constantin E Weinan Edriss S. Titi 《Communications in Mathematical Physics》1994,165(1):207-209
We give a simple proof of a result conjectured by Onsager [1] on energy conservation for weak solutions of Euler's equation. 相似文献
94.
This work extends to dismantable graphs many properties of dismantable posets dealing with products, exponentiation, existence of paths in a graph of all homomorphisms, fixed clique property, etc. We show that a poset is dismantlable in the sense of Rival if and only if its comparability graph is dismantlable, thus proving that, for posets, dismantlability is a comparability invariant. We establish the analogues for graphs of results of Duffus, Poguntke and Rival about fixed point sets and cores in posets. 相似文献
95.
We present a simple microscopic model to show how fluctuating two-level systems in a Josephson junction tunnel barrier of thickness L can modify the potential energy of the barrier and produce critical current noise spectra. We find low frequency 1/f noise that goes as L5. Our values are in good agreement with recent experimental measurements of critical current noise in Al/AlOx/Al Josephson junctions. We also investigate the sensitivity of the noise on the nonuniformity of the tunnel barrier. 相似文献
96.
97.
Mikhail Panfilov Constantin Oltean Irina Panfilova Michel Buès 《Comptes Rendus Mecanique》2003,331(1):41-48
The quadratic law of laminar flow through porous media at high Reynolds numbers, which is well confirmed by the multiple experimental data, is shown to give rise to three fundamental paradoxes. All them can be resolved by assuming the singular structure of flow. The singularity is produced by the formation of jet brunches which invade the stagnant zones and sharply loss their kinetic energy. The numerical simulation confirms this effect. To cite this article: M. Panfilov et al., C. R. Mecanique 331 (2003). 相似文献
98.
99.
Very large nonlinear unconstrained binary optimization problems arise in a broad array of applications. Several exact or heuristic techniques have proved quite successful for solving many of these problems when the objective function is a quadratic polynomial. However, no similarly efficient methods are available for the higher degree case. Since high degree objectives are becoming increasingly important in certain application areas, such as computer vision, various techniques have been recently developed to reduce the general case to the quadratic one, at the cost of increasing the number of variables by introducing additional auxiliary variables. In this paper we initiate a systematic study of these quadratization approaches. We provide tight lower and upper bounds on the number of auxiliary variables needed in the worst-case for general objective functions, for bounded-degree functions, and for a restricted class of quadratizations. Our upper bounds are constructive, thus yielding new quadratization procedures. Finally, we completely characterize all “minimal” quadratizations of negative monomials. 相似文献
100.