Corrigendum to "existence of equilibrium in single and double private value actions"

This is a corrigendum to Theorem 15 of Jackson and Swinkels (2005) [Existence of Equilibrium in Single and Double Private Value Auctions, Econometrica, 73, 93-140], which proves the existence of equilibrium with positive probability of trade for private value auctions

CORRIGENDUM TO "EXISTENCE OF EQUILIBRIUM IN SINGLE AND DOUBLE PRIVATE VALUE ACTIONS"

This is a corrigendum to Theorem 15 of Jackson and Swinkels (2005) [Existence of Equilibrium in Single and Double Private Value Auctions, Econometrica, 73, 93-140], which proves the existence of equilibrium with positive probability of trade for private value auctions.

Equilibria Existence in Regular Discontinuous Games

Many conditions have been introduced to weaken the continuity re- quirements for equilibrium existence in games. We introduce a new con- dition, called regularity, that is simple and easy to verify. It is implied both by Reny's better-reply security and Simon and Zame's endogenous sharing rule method. Regularity implies that the limits of epsilon-equilibria are equilibria. Since this condition is weak, it is yet not enough to ensure pure strategy equilibrium existence, but we are able to identify extra conditions that, together with regularity, are sufficient for equilibrium existence. One is the marginal continuity property introduced by Prokopovych (2008), while the second is the well behavior of a sequence of approximating con- tinuous functions. In this way, we provide new equilibrium existence re- sults for discontinuous games under conditions that are simpler and easier to check than most of the available alternatives.

Cyclic and ruled Lagrangian surfaces in complex Euclidean space

We study those Lagrangian surfaces in complex Euclidean space which are foliated by circles or by straight lines. The former, which we call cyclic, come in three types, each one being described by means of, respectively, a planar curve, a Legendrian curve of the 3-sphere or a Legendrian curve of the anti de Sitter 3-space. We also describe ruled Lagrangian surfaces. Finally we characterize those cyclic and ruled Lagrangian surfaces which are solutions to the self-similar equation of the Mean Curvature Flow. Finally, we give a partial result in the case of Hamiltonian stationary cyclic surfaces

Beyond the soft photon approximation in radiative production and decay of charged vector mesons

We study the effects of model-dependent contributions and the electric quadrupole moment of vector mesons in the decays $V^- \to P^-P^0\gamma$ and $\tau^- \to \nu V^-\gamma$. Their interference with the amplitude originating from the radiation due to electric charges vanishes for photons emitted collinearly to the charged particle in the final state. This brings further support to our claim in previous works, that measurements of the photon energy spectrum for nearly collinear photons in those decays are suitable for a first measurement of the magnetic dipole moment of charged vector mesons.Comment: 13 pages, 2 eps figures, Latex. Accepted for publication in Journal of Physics G: Nuclear and Particle Physics(2001

Current perspectives of the signaling pathways directing neural crest induction.

The neural crest is a migratory population of embryonic cells with a tremendous potential to differentiate and contribute to nearly every organ system in the adult body. Over the past two decades, an incredible amount of research has given us a reasonable understanding of how these cells are generated. Neural crest induction involves the combinatorial input of multiple signaling pathways and transcription factors, and is thought to occur in two phases from gastrulation to neurulation. In the first phase, FGF and Wnt signaling induce NC progenitors at the border of the neural plate, activating the expression of members of the Msx, Pax, and Zic families, among others. In the second phase, BMP, Wnt, and Notch signaling maintain these progenitors and bring about the expression of definitive NC markers including Snail2, FoxD3, and Sox9/10. In recent years, additional signaling molecules and modulators of these pathways have been uncovered, creating an increasingly complex regulatory network. In this work, we provide a comprehensive review of the major signaling pathways that participate in neural crest induction, with a focus on recent developments and current perspectives. We provide a simplified model of early neural crest development and stress similarities and differences between four major model organisms: Xenopus, chick, zebrafish, and mouse

PURE STRATEGY EQUILIBRIA OF SINGLE AND DOUBLE AUCTIONS WITH INTERDEPENDENT VALUES

We prove the existence of monotonic pure strategy equilibrium for many types of asymmetric auctions with n bidders and unitary demands, interdependent values and independent types. The assumptions require monotonicity only in the own bidder's type. The payments can be a function of all bids. Thus, we provide a new equilibrium existence result for asymmetrical double auctions and a small number of bidders. The generality of our setting requires the use of special tie-breaking rules. We present a reasonable counterexample for interdependent values auctions that shows that sometimes all equilibria are trivial, that is, they have zero probability of trade. Nevertheless, we give sufficient conditions for non-trivial equilibrium existence.

Bartering integer commodities with exogenous prices

The analysis of markets with indivisible goods and fixed exogenous prices has played an important role in economic models, especially in relation to wage rigidity and unemployment. This research report provides a mathematical and computational details associated to the mathematical programming based approaches proposed by Nasini et al. (accepted 2014) to study pure exchange economies where discrete amounts of commodities are exchanged at fixed prices. Barter processes, consisting in sequences of elementary reallocations of couple of commodities among couples of agents, are formalized as local searches converging to equilibrium allocations. A direct application of the analyzed processes in the context of computational economics is provided, along with a Java implementation of the approaches described in this research report.Comment: 30 pages, 5 sections, 10 figures, 3 table