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171.
《Mathematische Nachrichten》2017,290(5-6):756-773
Let be a connected reductive complex algebraic group with split real form . Consider a strict wonderful ‐variety X equipped with its σ‐equivariant real structure, and let X be the corresponding real locus. Further, let E be a real differentiable G‐vector bundle over X . In this paper, we introduce a distribution character for the regular representation of G on the space of smooth sections of E given in terms of the spherical roots of , and show that on a certain open subset of G of transversal elements it is locally integrable and given by a sum over fixed points. 相似文献
172.
《Mathematische Nachrichten》2017,290(16):2641-2647
Let G be a split semisimple algebraic group over a field k and let X be the flag variety (i.e., the variety of Borel subgroups) of G twisted by a generic G‐torsor. We start a systematic study of the conjecture, raised in 5 in form of a question, that the canonical epimorphism of the Chow ring of X onto the associated graded ring of the topological filtration on the Grothendieck ring of X is an isomorphism. Since the topological filtration in this case is known to coincide with the computable gamma filtration, this conjecture indicates a way to compute the Chow ring. We reduce its proof to the case of . For simply‐connected or adjoint G , we reduce the proof to the case of simple G . Finally, we provide a list of types of simple groups for which the conjecture holds. Besides of some classical types considered previously (namely, A, C, and the special orthogonal groups of types B and D), the list contains the exceptional types G2, F4, and simply‐connected E6. 相似文献
173.
《Mathematische Nachrichten》2017,290(17-18):2890-2900
The main result of this paper states that if C is a hyperelliptic curve of even genus over an arbitrary field K , then there is a natural bijection between the set of equivalence classes of elliptic subcovers of and the set of elliptic subgroups of its Jacobian . 相似文献
174.
Jaehyun Hong 《Transactions of the American Mathematical Society》2007,359(5):2361-2381
In this paper we study the space of effective -cycles in with the homology class equal to an integral multiple of the homology class of Schubert variety of type . When is a proper linear subspace of a linear space in , we know that is already complicated. We will show that for a smooth Schubert variety in a Hermitian symmetric space, any irreducible subvariety with the homology class , , is again a Schubert variety of type , unless is a non-maximal linear space. In particular, any local deformation of such a smooth Schubert variety in Hermitian symmetric space is obtained by the action of the Lie group .
175.
Three new phenolic compounds, irisdichototins D, E, and F ( 1 – 3 , resp.) were isolated from the stems of Iris dichotoma. The structures of the new compounds were elucidated by spectroscopic analyses, including 2D‐NMR techniques. 相似文献
176.
Edmond W. H. Lee 《代数通讯》2013,41(7):2275-2280
An exclusion variety is a variety that is maximal with respect to not containing some semigroup. It is shown that if the bases of all exclusion varieties for some periodic semigroup S are known, then the bases of exclusion varieties for the monoid S 1 can be computed. 相似文献
177.
Dimas José Gonçalves 《代数通讯》2013,41(12):5217-5235
178.
Ignacio Ojeda Martínez de Castilla 《代数通讯》2013,41(1):279-287
A commutative ring R is said to be strongly Hopfian if the chain of annihilators ann(a) ? ann(a 2) ? … stabilizes for each a ∈ R. In this article, we are interested in the class of strongly Hopfian rings and the transfer of this property from a commutative ring R to the ring of the power series R[[X]]. We provide an example of a strongly Hopfian ring R such that R[[X]] is not strongly Hopfian. We give some necessary and sufficient conditions for R[[X]] to be strongly Hopfian. 相似文献
179.
E. Ballico 《Linear and Multilinear Algebra》2013,61(7):881-894
We describe the stratification by tensor rank of the points belonging to the tangent developable of any Segre variety. We give algorithms to compute the rank and a decomposition of a tensor belonging to the secant variety of lines of any Segre variety. We prove Comon's conjecture on the rank of symmetric tensors for those tensors belonging to tangential varieties to Veronese varieties. 相似文献
180.
Any algebraic surface in which is fibered in cubics, so that the generic fibre is a twisted cubic, gives rise to a curve Γ in a suitable compactification
X of the space of smooth rational cubics of In this paper the case n = 4 is addressed and the corresponding space X is studied. We apply our results to complete the classification of smooth, rational surfaces in ruled in cubics.
This work is within the framework of the national research project “Geometry on Algebraic Varieties” Cofin 2006 of MIUR. 相似文献