U.S.-France Cooperative Research: Digraph Minors

美国佐治亚理工学院的罗宾·托马斯、普林斯顿大学的保罗·西摩、俄亥俄州立大学的g·尼尔·罗伯逊、巴黎第六大学的布鲁斯·里德研究组等人参加了这项为期三年的美法数学合作研究，并为三位美国研究人员提供了旅费和生活费。他们打算发展一种有向图小次的理论，特别强调树的分解。这个理论将类似于图小理论，它导致了高效的算法。该项目利用了法国在图小理论方面的专业知识，并将有助于建立一个新的结构理论。

This three-year award for U.S.-France cooperative research in mathematics involves Robin Thomas of Georgia Institute of Technology, Paul Seymour of Princeton University, G. Neil Robertson of Ohio State University and the research group of Bruce Reed of the University of Paris VI. The award provides travel support and living expenses to the three U.S. researchers. They intend to develop a theory of digraph minors with particular emphasis on tree decompositions. This theory will be analogous to graph minor theory which has led to efficient algorithms. The project takes advantage of French expertise in graph minor theory and will contribute towards a new structural theory.