Information Transfer Implies State Collapse

We attempt to clarify certain puzzles concerning state collapse and decoherence. In open quantum systems decoherence is shown to be a necessary consequence of the transfer of information to the outside; we prove an upper bound for the amount of coherence which can survive such a transfer. We claim that in large closed systems decoherence has never been observed, but we will show that it is usually harmless to assume its occurrence. An independent postulate of state collapse over and above Schroedinger's equation and the probability interpretation of quantum states, is shown to be redundant.Comment: 13 page

Review of the IMF's lending framework

In an effort to adapt to changes in its environment, the IMF has over the years adjusted its lending framework. Lending facilities have been created, abolished or modified, according to changing global circumstances. Nevertheless, these adaptations have often been made on an ad hoc basis. The article examines the current structure of IMF lending facilities and the policies governing them. It illustrates how some of the Fund’s lending facilities may have lost their relevance, that gaps could be perceived in the current lending framework and why the framework seems fragmented and overly complex. These issues can affect the credibility of the Fund’s lending framework and hence the perceived legitimacy of the institution. In order to address these issues, a comprehensive review of the IMF lending framework is direly needed. In fact, the Fund is currently reviewing its lending instruments and access policies in the context of its ongoing overall strategic review. This article seeks to provide an input into this process and, within this context, suggests three options for modernising the Fund’s lending framework. Under the first option, the spirit of the current multi-facility framework would be maintained, with a different facility for each type of financing need. In order to make this new multi-facility framework less complex and more internally consistent than the current set-up, a number of modifications are put forward to the policies governing it. A second option would involve the most far-reaching adjustment of the Fund’s lending framework, as it would replace the whole arsenal of IMF facilities with a single, flexible, SBA-type facility. Such a system is appealing for its simplicity, transparency and because it avoids the problem of having to analyse ex ante the type and expected duration of a member’s balance of payments needs. On the other hand, in order to be workable and to ensure uniformity of treatment, each lending decision would need to be based on clear rules and with due regard to precedents and the merits and requirements of each case. As an intermediary solution, the third option suggests replacing the current lending framework with a dual framework. Such a structure would comprise two facilities ; one facility for short- and one for medium- to longterm access or, alternatively, one facility for normal access and one for exceptional access to IMF resources.financial facilities, IMF, official lending, review

Systematics of heavy-ion fusion hindrance at extreme sub-barrier energies

The recent discovery of hindrance in heavy-ion induced fusion reactions at extreme sub-barrier energies represents a challenge for theoretical models. Previously, it has been shown that in medium-heavy systems, the onset of fusion hindrance depends strongly on the "stiffness" of the nuclei in the entrance channel. In this work, we explore its dependence on the total mass and the $Q$-value of the fusing systems and find that the fusion hindrance depends in a systematic way on the entrance channel properties over a wide range of systems.Comment: Submitted to Phys. Rev. Lett., 5 pages, 3 figure