Homotopy types of box complexes

In [MZ04] Matousek and Ziegler compared various topological lower bounds for the chromatic number. They proved that Lovasz's original bound [L78] can be restated as \chr G \geq \ind (\B(G)) +2. Sarkaria's bound [S90] can be formulated as \chr G \geq \ind (\B_0(G)) +1. It is known that these lower bounds are close to each other, namely the difference between them is at most 1. In this paper we study these lower bounds, and the homotopy types of box complexes. Some of the results was announced in [MZ04].Comment: 11 page

Screening Contracts in the Presence of Positive Network Effects

Based on the critical assumption of strategic complementarity, this paper builds a general model to describe and solve the screening problem faced by the monopolist seller of a network good. By applying monotone comparative static tools, we demonstrate that the joint presence of asymmetric information and positive network effects leads to a strict downward distortion for all consumers in the quantities provided. We also show that the equilibrium allocation is an increasing function of the intensity of network effects, and that a discriminating monopoly may supply large quantities for all consumers than a competitive industry.network effects, strategic complementarities, contracting with externalities, second-degree discrimination, monotone comparative statics

Debreceni Ember Pál ellopott és eltűnt könyvei

Egy disputációs kolligátum, egy 1642-es kálvinista kánon és egy Ember Pál saját kiadvány könyvészeti, filológiai leírása, eszmetörténeti tanulságokkal