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851.
We consider quantum unbounded spin systems (lattice boson systems) in -dimensional lattice space Z. Under appropriate conditions on the interactions we prove that in a region of high temperatures the Gibbs state is unique, is translationally invariant, and has clustering properties. The main methods we use are the Wiener integral representation, the cluster expansions for zero boundary conditions and for general Gibbs state, and explicitly -dependent probability estimates. For one-dimensional systems we show the uniqueness of Gibbs states for any value of temperature by using the method of perturbed states. We also consider classical unbounded spin systems. We derive necessary estimates so that all of the results for the quantum systems hold for the classical systems by straightforward applications of the methods used in the quantum case. 相似文献
852.
Given a family of Riemann surfaces and a holomorphic vector bundle Beilinson and Schechtman construct a canonical connection on the associated determinant bundle. We prove the conjecture which states that their connection coincides with the Quillen connection. This is done by reducing to the case where
along fibers are invertible. Both connection forms become more accessible in this case.Supported in part by N.S.F. Grant No. DMS-9201022Supported in part by National Science Council of Republic of China Grant No. NSC 82-0208-M-002-125-T, and NSERC of Canada Grant No. OGP 0121883 相似文献
853.
854.
钾原子中多种受激辐射参与的混频过程 总被引:2,自引:1,他引:1
当双原子共振激发钾原子于6S能级时,由光泵受激辐射和电离复合受激辐射参与的六波或四波混频,产生了位于紫外和紫区的诸多相干辐射、文中对多种混频机制进行了分析和讨论,并对所测得的相干辐射线进行了标识. 相似文献
855.
856.
The dilepton spectra from open charm decay inp+A reactions at $\sqrt s = 200$ AGeV are proposed to constrain gluon shadowing in nuclei. We show that the required measurements are feasible at RHIC. 相似文献
857.
858.
Denote bymi(G) the number of maximal independent sets ofG. This paper studies the setS(k) of all graphsG withmi(G) = k and without isolated vertices (exceptG K
1) or duplicated vertices. We determineS(1), S(2), andS(3) and prove that |V(G)| 2
k–1
+k – 2 for anyG inS(k) andk 2; consequently,S(k) is finite for anyk.
Supported in part by the National Science Council under grant NSC 83-0208-M009-050 相似文献
859.
Yong Zhang 《Order》1996,13(4):365-367
G. Grätzer, H. Lakser, and E. T. Schmidt proved that every distributive lattice with n join-irreducible elements can be represented as the congruence lattice of a small lattice L, that is, a lattice L with O(n
2
) elements. G. Grätzer, I. Rival, and N. Zaguia proved that, for any <2, O(n
2
) can not be improved to O(n
). In this note we show that the theorem about small representation can be improved further to get a more delicate result. 相似文献
860.
Kai-Ching Lin 《Transactions of the American Mathematical Society》1996,348(7):2663-2671
Let be a bounded smooth domain in , and a function with compact support in . Moser's inequality states that there is a constant , depending only on the dimension , such that
where is the Lebesgue measure of , and the surface area of the unit ball in . We prove in this paper that there are extremal functions for this inequality. In other words, we show that the
is attained. Earlier results include Carleson-Chang (1986, is a ball in any dimension) and Flucher (1992, is any domain in 2-dimensions).