Invited by Prof. Heping Zhang and associate Prof. Xianyue Li of School of Mathematics and Statistics, Prof. Xujin Chen from Academy of Mathematics and Systems Science, Chinese Academy of Sciences will give a lecture.

Title: Single-Candidate Reverse Voting in a Metric Space

Time: 9:20 a.m.,May. 8th, 2021

Location: Lecture hall on the second floor,Shaw Science Museum

Abstract: We study single-candidate voting embedded in a metric space. Both voters and candidates are points in the space. The distances between voters and candidates specify the voters’ preferences over candidates. Each voter submits her favorite candidate to a mechanism that does not know voters’ locations. The mechanism outputs the least popular candidate, i.e., finds a committee containing the other candidates. Each committee is associated with a social value – the sum of the costs (utilities) it imposes (provides) to the voters. We design mechanisms for finding a committee to optimize the social value. We measure the quality of a mechanism by its distortion, i.e., the worst-case ratio between the social value of the committee found by the mechanism and the optimal one. We establish upper and lower bounds on mechanism distortion for this single-candidate voting in general metrics and well-motivated special cases. (Joint work with Minming Li and Chenhao Wang.)