This project is to develop theoretic foundations and practical algorithms for geometric analysis of massive, weighted graphs arising from computer networking applications. The main challenge of understanding large scale computer networking is the decentralized management and operations on the network. How the global behaviors (for example, congestion) emerge from decentralized, local operations (routing) is still a mystery. Differential geometry studies the connection of local structures (such as curvatures) and global properties (such as topology and geodesics). Geometric analysis theorems often naturally lead to distributed algorithms that achieve global objectives, which is ideal in networking applications.
This project generalizes classical geometric analysis methods to massive graphs, the theoretic exploration focuses on the curvatures on graphs and the heat kernel estimates, relation between optimal transportation on graphs and curvatures, Ricci flow on graphs, and homology/cohomology/homotopy groups on directed graphs. The theoretic results will be applied for studying fundamental problems in computer networks, including: 1) Geodesics and network congestion: which aims to understand the connection of network congestion (e.g., on the Internet) with network curvature, and try to apply Ricci flow to alleviate network congestion by modifying local curvature; 2) Graph embedding and efficient routing: which investigates how to find an embedding of the network in geometric space in order to support greedy routing; and 3) Resource allocation in wireless networks: which applies optimal transport theory to the problem of capacitated base station allocation. The research results will be useful for applications in a broad range of fields, from pure mathematics research to theoretic physics, from telecommunication in engineering to brain imaging in medicine.
