Let G be the group of projectivities stabilizing a unital U in PG(2, q2). In this paper, we prove that U is a classical unital if and only if there are two points in U such that the stabilizer of these two points in G has order q2 − 1.

In this note we show that the results developed in Singh and Vives (1984) are sensitive to the duopoly assumption (Rand Journal of Economics 15, 546-554). If there are more than two firms, prices may be higher under price competition than under quantity competition. This will be the case if quality differences are large and goods are complements. If goods are substitutes, high-quality firms may...

ELECTIONS AND ASSET PRICING: THE POLITICALLY SENSITIVE EQUITY OF US MILITARY CONTRACTORS by

In contrast with the classical models of frictionless financial markets, market models with proportional transaction costs, even satisfying usual no-arbitrage properties, may admit arbitrage opportunities of the second kind. This means that there are self-financing portfolios with initial endowments laying outside the solvency region but ending inside. Such a phenomenon was discovered by M. Rás...

Focus is here on coalitional games among economic agents plagued by aggregate pollutions of diverse sorts. Defecting players presumably pollute more than others. Then, granted convex preferences and technologies, the core is proven nonempty. In fact, under natural assumptions, a specific, computable core solution comes in terms of shadow prices on the said aggregates. Such prices may, in large ...

For portfolio choice problems with proportional transaction costs, we discuss whether or not there exists a shadow price, i.e., a least favorable frictionless market extension leading to the same optimal strategy and utility. By means of an explicit counter-example, we show that shadow prices may fail to exist even in seemingly perfectly benign situations, i.e., for a log-investor trading in an...

We consider dilaton stabilization with R invariance, which insures a vanishing cosmological constant at the scale of stabilization. We construct a few models which accommodate weak gauge couplings with large or small gauge groups. Matter condensation plays a central role in the dilaton stabilization.

Kutten and Patt-Shamir have proposed a method for fast recovery of the output of a non-reactive, distributed protocol: if f < n=2 processors are corrupted from a legitimate global state, then the method recovers the output in O(f) time. The proposed method leaves open the case f n=2. This note presents a technique to handle also the case of f n=2, again recovering the output in O(f) time. The r...

A randomized uniform self-stabilizing protocol that provides each (anonymous) processor of a uniform system with a distinct identiier is presented. The protocol uses a predeened xed amount of memory and stabilizes within expected (d) time, where d is the actual diameter of the network.