Heavy Quarkonium in the Quark Gluon Plasma from Effective Field Theories and Potentials

The measurements of heavy quarkonium suppression at RHIC and LHC urge theory to develop intuitive as well as quantitative methods for the description of $Q\bar{Q}$ melting in the quark-gluon plasma. Here I will present a brief sketch on the effective field theory strategies underlying the definition of the heavy quark static potential and report on two recent advances in the extraction and interpretation of such a potential. On the one side, progress has been made in obtaining its values from lattice QCD, which promises to make possible investigating its real and imaginary part non-perturbatively. On the other side, the existence of an imaginary part emphasizes the dynamical nature of the melting process and invites us to make a direct connection to the framework of open quantum systems.Comment: Talk given at the 5th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions 2012, to be published in Nucl. Phys. A, 8 pages, 1 figure, (v2 replaced one reference, corrected typos

Dictators and Their Viziers: Agency Problems in Dictatorships

The possibility of treason by a close associate has been a nightmare of most dictators throughout history. Better informed viziers are also better able to discriminate among potential plotters, and this makes them more risky subordinates for the dictator. To avoid this, dictators, especially which are weak and vulnerable, sacri.ce the competence of their agents, hiring mediocre but loyal subordinates. One reason why democracies generally witness more talented people in the government is the dictator.s inability to commit to the optimal (less than the capital) punishment for those who unsuccessfully plotted to remove him from power. Furthermore, any use of incentive schemes by a dictator is limited by the fact that rewards are conditional on dictator.s own willingness to keep his promises, while punishments are conditional on dictator.s own survival. We model a principalagent game between a dictator and his (probably, few) viziers both in static and dynamic perspectives. The dynamic model allows us to focus on the succession problem the insecure dictators face.dictatorship, formal political theory, principal-agent theory, institutions

The prediction of future behavior: The empty promises of expert clinical and actuarial testimony

Testimony about the future dangerousness of a person has become a central staple of many judicial processes. In settings such as bail, sentencing, and parole decisions, in rulings about the civil confinement of the mentally ill, and in custody decisions in a context of domestic violence, the assessment of a person’s propensity towards physical or sexual violence is regarded as a deciding factor. These assessments can be based on two forms of expert testimony: actuarial or clinical. The purpose of this paper is to examine the scientific and epistemological basis of both methods of prediction or risk assessment. My analysis will reveal that this kind of expert testimony is scientifically baseless. The problems I will discuss will generate a dilemma for factfinders: on the one hand, given the weak predictive abilities of the branches of science involved, they should not admit expert clinical or actuarial testimony as evidence; on the other hand, there is a very strong tradition and a vast jurisprudence that supports the continued use of this kind of expert testimony. It is a clear case of the not so uncommon conflict between science and legal tradition

Do Android Taint Analysis Tools Keep Their Promises?

In recent years, researchers have developed a number of tools to conduct taint analysis of Android applications. While all the respective papers aim at providing a thorough empirical evaluation, comparability is hindered by varying or unclear evaluation targets. Sometimes, the apps used for evaluation are not precisely described. In other cases, authors use an established benchmark but cover it only partially. In yet other cases, the evaluations differ in terms of the data leaks searched for, or lack a ground truth to compare against. All those limitations make it impossible to truly compare the tools based on those published evaluations. We thus present ReproDroid, a framework allowing the accurate comparison of Android taint analysis tools. ReproDroid supports researchers in inferring the ground truth for data leaks in apps, in automatically applying tools to benchmarks, and in evaluating the obtained results. We use ReproDroid to comparatively evaluate on equal grounds the six prominent taint analysis tools Amandroid, DIALDroid, DidFail, DroidSafe, FlowDroid and IccTA. The results are largely positive although four tools violate some promises concerning features and accuracy. Finally, we contribute to the area of unbiased benchmarking with a new and improved version of the open test suite DroidBench

A process algebra based framework for promise theory

We present a process algebra based approach to formalize the interactions of computing devices such as the representation of policies and the resolution of conflicts. As an example we specify how promises may be used in coming to an agreement regarding a simple though practical transportation problem.Comment: 9 pages, 4 figure

Electoral Control when Policies are for Sale

This article analyses the dynamics of electoral promises, building on an electoral competition model with endogenous policies. It extends the Grossman-Helpman (1994) model [Grossman G., Helpman E. [1994], "Protection for sale", American Economic Review, 84, 4, 833-850] to include sanctions from the electorate and lobbies when the incumbent does not satisfy the expected performance she promised to deliver. This framework allows to deal with the intertemporal dimension needed to understand the prevalent cycle of promises, disappointment, new promises, new disappointment ….lobbies, promises, elections, electoral competition, lies

Haggling for Rents, Relational Contracts, and the Theory of the Firm

In this paper, a formal rent-seeking theory of the firm is developed. The main idea is that integration (compared to non-integration) facilitates rent-seeking for the integrating party, but makes it harder for the integrated one. In a one-period model, this implies that the rent-seeking contest becomes more uneven and the parties rent-seek less. Here, integration is optimal. In the infinitely-repeated version of the model, it is also possible for the parties to enter a relational contract, under which each promises not to engage in rent-seeking. Such a contract must be self-enforcing, for it cannot be enforced by court. It is shown that integration makes the relational contract less easily sustainable, as, due to its cost advantage, the integrating party gains more from deviating than any party under non-integration. Hence, integration is preferred, if relational contracts are not sustainable, while, otherwise, non-integration may well be preferred. Moreover, it is shown that the model’s predictions are in line with many empirical facts on the choice of ownership structures

Norms and the Theory of the Firm

This paper discusses some of the attempts economists have made in the last ten years or so to integrate norms into the theory of the firm. The paper argues that (a) although norms are undoubtedly very important both inside and between firms, incorporating them into the theory has been very difficult and is likely to continue to be so in the near future; (b) so far norms have not added a great deal to our understanding of such issues as the determinants of firm boundaries (the "make-or-buy" decision)--that is, at this point a norm-free theory of the firm and a norm-rich theory of the firm don’t seem to have very different predictions.