Does timing of decisions in a mixed duopoly matter?

We determine the endogenous order of moves in a mixed price-setting duopoly. In contrast to the existing literature on mixed oligopolies we establish the payoff equivalence of the games with an exogenously given order of moves. Hence, it does not matter whether one becomes a leader or a follower. We also establish that replacing a private firm by a public firm in the standard Bertrand-Edgeworth game with capacity constraints increases social welfare and that a pure-strategy equilibrium always exists.Bertrand-Edgeworth; mixed duopoly; timing games

Post-selected weak measurement beyond the weak value

Closed expressions are derived for the quantum measurement statistics of pre-and postselected gaussian particle beams. The weakness of the pre-selection step is shown to compete with the non-orthogonality of post-selection in a transparent way. The approach is shown to be useful in analyzing post-selection-based signal amplification, allowing measurements to be extended far beyond the range of validity of the well-known Aharonov-Albert-Vaidman limit.Comment: The published version; with respect to previous one, note changes in Eqs. (16),(17),(19)

Unjamming of Granular Packings due to Local Perturbations: Stability and Decay of Displacements

We study the mechanical response generated by local deformations in jammed packings of rigid disks. Based on discrete element simulations we determine the critical force of the local perturbation that is needed to break the mechanical equilibrium and examine the generated displacement field. Displacements decay as a power law of the distance from the perturbation point. The decay exponent and the critical force exhibit nontrivial dependence on the friction: Both quantities are nonmonotonic and have a sharp maximum at the friction coefficient 0.1. We find that the mechanical response properties are closely related to the problem of force-indeterminacy where similar nonmonotonic behavior was observed previously. We establish direct connection between the critical force and the ensemble of static force networks.Comment: 4 pages, 4 figure

Thermal stability of the microstructure of severely deformed copper

Copper specimens were deformed by equal channel angular pressing (ECAP) up to 8 passes. The microstructure was studied by X-ray line profile analysis. The crystallite size is reduced to a few tens of nanometers even after the first ECAP pass and it does not change significantly during further deformation. At the same time, the dislocation density increases gradually up to 4 ECAP passes. The thermal stability of the microstructure is examined by differential scanning calorimetry (DSC). The temperature of the DSC peak decreases whereas the stored energy increases with increasing strain. At the beginning of the heat release a bimodal grain structure develops indicated by a special double-peak shape of the diffraction line profiles

Extent of force indeterminacy in packings of frictional rigid disks

Static packings of frictional rigid particles are investigated by means of discrete element simulations. We explore the ensemble of allowed force realizations in the space of contact forces for a given packing structure. We estimate the extent of force indeterminacy with different methods. The indeterminacy exhibits a nonmonotonic dependence on the interparticle friction coefficient. We verify directly that larger force-indeterminacy is accompanied by a more robust behavior against local perturbations. We also investigate the local indeterminacy of individual contact forces. The probability distribution of local indeterminacy changes its shape depending on friction. We find that local indeterminacy tends to be larger on force chains for intermediate friction. This correlation disappears in the large friction limit.Comment: 5 pages, 6 figure

To make a nanomechanical Schr\"{o}dinger-cat mew

By an explicite calculation of Michelson interferometric output intensities in the optomechanical scheme proposed by Marshall et al. (2003), an oscillatory factor is obtained that may go down to zero just at the time a visibility revival ought to be observed. Including a properly tuned phase shifter offers a simple amendment to the situation. By using a Pockels phase shifter with fast time-dependent modulation in one arm, one may obtain further possibilities to enrich the quantum state preparation and reconstruction abilities of the original scheme, thereby improving the chances to reliably detect genuine quantum behaviour of a nanomechanical oscillator.Comment: For Proc. DICE-2010 (Castiglioncello), to be published in J. Phys. Conf. Ser., 201