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Quadratic groups, whose definitions depend on form parameters, contain the orthogonal groups, symplectic groups, classical unitary groups and all the classical groups of Dieudonné [4] as well as those of Bruhat and Tits [2]. Gauss decomposition with prescribed semisimple part in these groups is presented. As an application, the analog of a conjecture of Thompson is also studied for these groups. 相似文献
955.
Helmut Zöschinger 《代数通讯》2013,41(6):1977-1994
Let (R, 𝔪) be a commutative, noetherian, local ring, E the injective hull of the residue field R/𝔪, and M ○○ = Hom R (Hom R (M, E), E) the bidual of an R-module M. We investigate the elements of Ass(M ○○) as well as those of Coatt(M) = {𝔭 ∈ Spec(R)|𝔭 = Ann R (Ann M (𝔭))} and provide criteria for equality in one of the two inclusions Ass(M) ? Ass(M ○○) ? Coatt(M). If R is a Nagata ring and M a minimax module, i.e., an extension of a finitely generated R-module by an artinian R-module, we show that Ass(M ○○) = Ass(M) ∪ {𝔭 ∈ Coatt(M)| R/𝔭 is incomplete}. 相似文献
956.
Murat Alan 《代数通讯》2013,41(11):4089-4099
Let R be a commutative ring with identity. R is a finite factorization ring (FFR) if every nonzero nonunit of R has only a finite number of factorizations up to order and associates. In this article, we give a characterization of R for R[X] and R[[X]] to be an FFR. 相似文献
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958.
Benjamin Fine Olga G. Kharlampovich Alexei G. Myasnikov Vladimir N. Remeslennikov G. Rosenberger 《代数通讯》2013,41(8):3386-3394
We prove that the automorphism group of a finitely generated fully residually free group is tame. 相似文献
959.
Huyên Pham 《Stochastics An International Journal of Probability and Stochastic Processes》2013,85(5):343-368
Motivated by the theory of bond markets, we consider an infinite assets model driven by marked point process and Wiener process. The self-financed wealth processes are defined by using measure-valued strategies. Going further on the works of Bjork et al. [“Bond market structure in the presence of marked point processes”, Mathematical Finance, 7 (1997a) pp. 211–239; “Towards a general theory of bond markets”, Finance and Stochastics, 1 (1997b) pp. 141–174] who focus on the existence of martingale measures and market completeness questions, we study here the incompleteness case. Our main result is a predictable decomposition theorem for supermartingales in this infinite assets model context. The concept of approximate wealth processes is introduced, and we show in an example that the space of measure-valued strategies is not complete with respect to the semimartingale topology. As in the case of stock markets, one can then derive a dual representation of the super-replication cost and study the problem of utility maximization by duality methods. 相似文献
960.