Internet Advertising and the Generalized Second Price Auction: Selling Billions of Dollars Worth of Keywords

We investigate the "generalized second price" auction (GSP), a new mechanism which is used by search engines to sell online advertising that most Internet users encounter daily. GSP is tailored to its unique environment, and neither the mechanism nor the environment have previously been studied in the mechanism design literature. Although GSP looks similar to the Vickrey-Clarke-Groves (VCG) mechanism, its properties are very different. In particular, unlike the VCG mechanism, GSP generally does not have an equilibrium in dominant strategies, and truth-telling is not an equilibrium of GSP. To analyze the properties of GSP in a dynamic environment, we describe the generalized English auction that corresponds to the GSP and show that it has a unique equilibrium. This is an ex post equilibrium that results in the same payoffs to all players as the dominant strategy equilibrium of VCG.

Existence of nearly holomorphic sections on compact Hermitian symmetric spaces

Let $X=U/K$ be a compact Hermitian symmetric space, and let \sE be a $U$-homogeneous Hermitian vector bundle on $X$. In a previous paper, we showed that the space of nearly holomorphic sections is well-adapted for harmonic analysis in L^2(X,\sE) provided that non-trivial nearly holomorphic sections do exist. Here we investigate the problem of extending local nearly holomorphic sections to global ones and prove the existence of non-trivial nearly holomorphic sections. This extends the results on the $U$-type decomposition of L^2(X,\sE) from our previous paper.Comment: 20 page

Jordan theoretic G-orbits and flag varieties

The Jordan theoretic approach to bounded symmetric domains G/K is used to determine the G-orbits on the compact dual of G/K as well as their Matsuki-duals in an explicit way. For this we use a generalized version of the Peirce decomposition within Jordan triple systems and the notion of pseudo-inverses. As a second result of this thesis we develope a Jordan theoretic model for generalized flag varieties and use this to give a Jordan theoretic description of the so called determinant functions introduced by L. Barchini, S.G. Gindikin and H.W. Wong