Speaker: Adam Sheffer, TAU Title: Approximations via Semidefinite Programming: An Introduction Abstract: Semidefinite programming (or SDP) is a subfield of convex optimization, which arose as a generalization of linear programming with many novel applications. One such "recent" application is a powerful framework for approximation algorithms. Currently, SDP-based algorithms obtain the best approximation ratios for many major problems, such as graph coloring, maximum cut, and Max-SAT. In this talk, we try to provide a simple introduction to SDP-based approximation algorithms, which seem to be a useful tool for theoretical computer scientists. We will go over some theoretical background required for the technique, present the technique by using some examples from the founding paper [Goemans and Williamson `95], and discuss the analysis in [Karger, Motwani, and Sudan `98] which has a more geometric flavor. No recent results will be surveyed, and the talk will probably be too basic for people who are already familiar with the subject.