报告题目：Evaluating EYM amplitudes in 4d by refined graphic rule

报告人：杜一剑   副教授（武汉大学）

报告时间：2020 年 10 月 29 日（周四）15：30

报告地点：在线报告（ 腾讯会议 ID : 537 4946 4937）

报告摘要：

The recursive expansion of tree level multi-trace Einstein-Yang-Mills (EYM) amplitudes induces a refined graphic rule, by which any tree-level EYM amplitude can be expanded in terms of pure Yang-Mills (YM) amplitudes. This graphic expansion allows us to evaluate EYM amplitudes through YM amplitudes, the latter have much simpler structures in four dimensions. In this talk, we investigate the MHV sector in the refined-graphic expansion of EYM amplitudes and then evaluate the MHV amplitudes in four-dimensions at both single- and double-trace levels. For single-trace MHV amplitudes, we establish the correspondence between the graphs defined by the refined graphic rule and the spanning forests of the Hodges determinant form in four dimensions. This correspondence is then extended to double-trace MHV amplitudes: we propose a symmetric expression for double-trace MHV amplitudes.

报告人简介：杜一剑，2005年在浙江大学取得学士学位，2010年在浙江大学取得博士学位，2010年-2015年先后在浙江大学、复旦大学、隆德大学从事博士后工作。2015年至今，武汉大学副教授。