双曲空间中三种模型的测地线研究

文章主要研究并给出负常曲率空间中三种模型的测地线的研究结果。

On a Quasilinear Hyperbolic System Relative to an Atmospheric Model on the Transition of Water Defined on the Whole Space

In this paper we study a quasi-linear hyperbolic system, with some integral operators, arising from an atmospheric model on the transition of water. By using the method of characteristics and a fixed point argument, we prove a theorem of existence, uniqueness and continuous dependence on data, in Lipschitz class, of the solution to this problem.

On the algorithmic construction of classifying spaces and the isomorphism problem for biautomatic groups

We show that the isomorphism problem is solvable in the class of central extensions of word-hyperbolic groups,and that the isomorphism problem for biautomatic groups reduces to that for biautomatic groups with finite centre.We describe an algorithm that,given an arbitrary finite presentation of an automatic group Γ,will construct explicit finite models for the skeleta of K(Γ,1) and hence compute the integral homology and cohomology of Γ.