An Experimental Investigation of Entry Cost Effects in Sealed Bid Dollar Auctions

In numerous auction settings potential bidders incur costs to enter the auction. Such costs may potentially influence bidder’s behavior subsequently. In this paper we experimentally study the effect of entry costs on bidding and entry behavior, through a complete information common value auction. We run first and second price auctions both with and without entry costs. We find that with entry costs, players on average bid lower in first price auctions, while in second price auctions the average bids are higher, compared to bids in the corresponding no entry fee auctions.Common Value Auctions, Entry Costs, Experiments

Religious fragmentation, social identity and cooperation: Evidence from a artefactual field experiment in India

We study the role of village-level religious fragmentation on intra- and inter-group cooperation in India. We report on data on two-player Prisoners Dilemma and Stag Hunt experiments played by 516 Hindu and Muslim participants in rural India. Our treatments are the identity of the two players and the degree of village-level religious heterogeneity. In religiously-heterogeneous villages, cooperation rates in the Prisoners Dilemma are higher when subjects play with another in-group member for both Hindus and Muslims, but to a much lesser extent in the Stag Hunt game. This suggests that positive in-group biases operate primarily on the willingness to achieve socially efficient outcomes, rather than through beliefs about the actions by one’s counterpart. Interestingly, cooperation rates among people of the same religion are significantly lower in homogeneous villages than in fragmented villages in both games. This is likely because a sense of group identity is only meaningful in the presence of an outgroup. This, together with little evidence for out-group prejudice in either game, means religious diversity is beneficial

Interacting fermions in synthetic non-Abelian gauge fields

Generation and study of synthetic gauge fields has enhanced the possibility of using cold atom systems as quantum emulators of condensed matter Hamiltonians. In this article we describe the physics of interacting spin -1/2 fermions in synthetic non-Abelian gauge fields which induce a Rashba spin-orbit interaction on the motion of the fermions. We show that the fermion system can evolve to a Bose-Einstein condensate of a novel boson which we call rashbon. The rashbon-rashbon interaction is shown to be independent of the interaction between the constituent fermions. We also show that spin-orbit coupling can help enhancing superfluid transition temperature of weak superfluids to the order of Fermi temperature. A non-Abelian gauge field, when used in conjunction with another potential, can generate interesting Hamiltonians such as that of a magnetic monopole

Online Algorithms with Discrete Visibility - Exploring Unknown Polygonal Environments

The context of this work is the exploration of unknown polygonal environments with obstacles. Both the outer boundary and the boundaries of obstacles are piecewise linear. The boundaries can be nonconvex. The exploration problem can be motivated by the following application. Imagine that a robot has to explore the interior of a collapsed building, which has crumbled due to an earthquake, to search for human survivors. It is clearly impossible to have a knowledge of the building's interior geometry prior to the exploration. Thus, the robot must be able to see, with its onboard vision sensors, all points in the building's interior while following its exploration path. In this way, no potential survivors will be missed by the exploring robot. The exploratory path must clearly reflect the topology of the free space, and, therefore, such exploratory paths can be used to guide future robot excursions (such as would arise in our example from a rescue operation)

Zaciskające zapalenie osierdzia imitujące ciężką restenozę zastawki mitralnej u chorego po leczeniu chirurgicznym choroby reumatycznej serca

Pericardial constriction is a rare, but well documented complication following cardiac surgery. It has been reported following coronary artery bypass grafting (CABG), cardiac surgery for congenital heart diseases and very rarely following closed mitral commissurotomy. We hereby report a case of chronic constrictive pericarditis following closed mitral commissurotomy mimicking mitral restenosis with refractory heart failure

An experimental investigation of entry cost effects in sealed bid dollar auctions

Discussion paperIn numerous auction settings potential bidders incur costs to enter the auction. Such costs may potentially influence bidder’s behavior subsequently. In this paper we experimentally study the effect of entry costs on bidding and entry behavior, through a complete information common value auction. We run first and second price auctions both with and without entry costs. We find that with entry costs, players on average bid lower in first price auctions, while in second price auctions the average bids are higher, compared to bids in the corresponding no entry fee auctions.Author's draft issued as discussion paper. Final version published by Elsevier; available online at http://www.sciencedirect.com

Time-reversal symmetry breaking in superconductors through loop supercurrent order

We propose a novel superconducting ground state where microscopic supercurrent loops form spontaneously within a unit cell at the superconducting transition temperature with only uniform, onsite and intra-orbital singlet pairing. As a result of the circulating currents time-reversal symmetry (TRS) is spontaneously broken in the superconducting state. Using Ginzburg–Landau theory we describe in detail how these currents emerge in a toy model. We discuss the crystallographic symmetry requirements more generally to realize such a state and show that they are met by the Re6X (X = Zr, Hf, Ti) family of TRS-breaking, but otherwise seemingly conventional, superconductors. We estimate an upper bound for the resulting internal magnetic fields and find it to be consistent with recent muon-spin relaxation experiments

Quantitative theory of triplet pairing in the unconventional superconductor LaNiGa2

The exceptionally low-symmetry crystal structures of the time-reversal symmetry-breaking superconductors LaNiC2 and LaNiGa2 lead to an internally antisymmetric nonunitary triplet state as the only possibility compatible with experiments. We argue that this state has a distinct signature: a double-peak structure in the density of states (DOS) which resolves in the spin channel in a particular way. We construct a detailed model of LaNiGa2 capturing its electronic band structure and magnetic properties ab initio. The pairing mechanism is described via a single adjustable parameter. The latter is fixed by the critical temperature Tc allowing parameter-free predictions. We compute the electronic specific heat and find excellent agreement with experiment. The size of the ordered moment in the superconducting state is compatible with zero-field muon spin relaxation experiments and the predicted spin-resolved DOS suggests the spin splitting is within the reach of present experimental technology

Recent progress on superconductors with time-reversal symmetry breaking

Superconductivity and magnetism are antagonistic states of matter. The presence of spontaneous magnetic fields inside the superconducting state is, therefore, an intriguing phenomenon prompting extensive experimental and theoretical research. In this review, we discuss recent experimental discoveries of unconventional superconductors which spontaneously break time-reversal symmetry and theoretical efforts in understanding their properties. We discuss the main experimental probes and give an extensive account of theoretical approaches to understand the order parameter symmetries and the corresponding pairing mechanisms including the importance of multiple bands