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991.
环上矩阵方程AXB+CYD=E的可解性 总被引:6,自引:0,他引:6
设R为一个含幺环,应用矩阵的{1,2}-逆(存在的前提下),本文得到R上矩阵方程AXB+CYD=E有解的充要条件以及一般解的公式,并且推广了著名的Roth等价定理。 相似文献
992.
Using the coset construction, we compute the root multiplicities at level-3 for some hyperbolic Kac–Moody algebras including the basic hyperbolic extension of A1
1 and E10. 相似文献
993.
We study a category of representations over a semisimple Lie algebra, which contains category as well as the so-called Whittaker modules, and prove a generalization of the Kazhdan-Lusztig conjectures in this context.
Received: January 15, 1996 相似文献
994.
Alexandros Patsourakos 《Letters in Mathematical Physics》1997,41(4):391-402
In this Letter, we construct a natural contracting homotopy in the usual cochain complex of free Lie algebras. As a consequence, we prove that the triple cohomology of Lie algebras coincides with a slightly different form of the standard cohomology theory. 相似文献
995.
B. A. Rosenfeld 《Acta Appl Math》1998,50(1-2):103-110
In this paper the geometric interpretation of the exceptional Lie groups F4, E6, E7, and E8 is given. These groups are groups of motions of elliptic hyperbolic planes over nonassociative algebras of octaves and split octaves and their tensor products with algebras of usual and split complex numbers, quaternions and octaves. The explicit expressions of motions of these planes and their figures of symmetry are presented. 相似文献
996.
Enrico Leuzinger 《Differential Geometry and its Applications》2004,20(3):141-318
The results in this paper are based on a previously constructed exhaustion of a locally symmetric space V=ΓX by Riemannian polyhedra, i.e., compact submanifolds with corners: V=s0V(s). We show that the interior of every polyhedron V(s) is homeomorphic to V. The universal covering space X(s) of V(s) is quasi-isometric to the discrete group Γ. It can be written as the complement of a Γ-invariant union of horoballs in X (which in general have intersections giving rise to the corners). This yields exponential isoperimetric inequalities for Γπ1(V(s)). We also discuss the relation of this compactification of V with the Borel–Serre compactification. 相似文献
997.
A set-covering problem is called regular if a cover always remains a cover when any column in it is replaced by an earlier column. From the input of the problem - the coefficient matrix of the set-covering inequalities - it is possible to check in polynomial time whether the problem is regular or can be made regular by permuting the columns. If it is, then all the minimal covers are generated in polynomial time, and one of them is an optimal solution. The algorithm also yields an explicit bound for the number of minimal covers. These results can be used to check in polynomial time whether a given set-covering problem is equivalent to some knapsack problem without additional variables, or equivalently to recognize positive threshold functions in polynomial time. However, the problem of recognizing when an arbitrary Boolean function is threshold is NP-complete. It is also shown that the list of maximal non-covers is essentially the most compact input possible, even if it is known in advance that the problem is regular. 相似文献
998.
IRREDUCIBLE REPRESENTATIONS FOR THE AFFINE-VIRASORO LIE ALGEBRA OF TYPE B_l 总被引:1,自引:0,他引:1
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An explicit construction of irreducible representations for the affine-Virasoro Liealgebra of type B_l, through the use of vertex operators and certain oscillator represen-tations of the Virasoro algebra, is given. 相似文献
999.
XU Mingchun 《中国科学A辑(英文版)》2006,49(9)
In this paper the author has solved a problem of Abe and liyori for the finite simple groups 2F4(q) and 2F4(2)'. 相似文献
1000.
DONG Zhong-Zhou LIU Xi-Qiang BAI Cheng-Lin 《理论物理通讯》2006,46(1):15-20
Using the classical Lie method of infinitesimals, we first obtain the symmetry of the (2+1)-dimensional Burgers-Korteweg-de-Vries (3D-BKdV) equation. Then we reduce the 3D-BKdV equation using the symmetry and give some exact solutions of the 3D-BKdV equation. When using the direct method, we restrict a condition and get a relationship between the new solutions and the old ones. Given a solution of the 3D-BKdV equation, we can get a new one from the relationship. The relationship between the symmetry obtained by using the classical Lie method and that obtained by using the direct method is also mentioned. At last, we give the conservation laws of the 3D-BKdV equation. 相似文献