Sudden Decoherence Transitions for Quantum Discord

We investigate the disappearance of discord in 2- and multi-qubit systems subject to decohering influences. We formulate the computation of quantum discord in terms of the generalized Bloch vector, which gives useful insights on the time evolution of quantum coherence for the open system, particularly the comparison of entanglement and discord. And we show that the analytical calculation of the global geometric discord is NP-hard in the number of qubits. We present an efficient numerical method to calculating the quantum discord for a certain important class of multipartite states. In agreement with previous work for 2-qubit cases, (Mazzola et al., Phys. Rev. Lett. 104, 200401 (2010)), we find situations in which there is a sudden transition from classical to quantum decoherence characterized by the discord remaining relatively robust (classical decoherence) until a certain point from where it begins to decay quickly whereas the classical correlation decays more slowly (quantum decoherence). However, we find that as the number of qubits increases, the chance of this kind of transition occurring becomes small.Comment: 15 pages, 2 figure

The Incidence of Long-Term Unemployment in Australia 1978-2003

This paper explores the following question - Has there been any long-run increase (or decrease) in the ‘incidence’ of long-term unemployment once we have corrected for cyclical factors? Our research leads us to conclude: (i) that the incidence of male long-term unemployment has been neither rising nor falling, once we allow for ‘cyclical factors’ and, (ii) that the incidence of female long-term unemployment has been rising, once we allow for ‘cyclical factors’. We conjecture that there is a link between increasing female participation (which we take to be a proxy for ‘attachment to the labour market’ – and thus attachment to unemployment as well as employment) and an increasing incidence of long-term unemployment. Experimenting with policy dummies, we find no evidence of policy effects on the incidence of long-term unemployment in the case of males and females but there is some evidence that policy had temporary effects on females.Unemployment Business Cycle

Epilepsy Therapy Goes Viral.

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Underlying Inflation in Australia: Are the Existing Measures Satisfactory?

Along with a number of other central banks around the world the Reserve Bank of Australia has quite explicitly adopted an inflation target. Both the Bank and the Australian Government’s statistical agency (the Australian Bureau of Statistics) report various measures of the underlying rate of inflation. The aim of this paper is to formulate criteria which an acceptable underlying rate must satisfy and then test to see whether either individually or in combination any of the current (CPI Excluding volatile items; CPI Market prices excluding volatile items; Weighted median and; Trimmed mean) or recently discarded (the Treasury underlying rate) measures of underlying inflation satisfy these criteria. We find that for the period since inflation targeting began (in 1993) none of these underlying series satisfy all of the criteria we propose but that one series (the RBA’s Trimmed mean series) does satisfy the sub-set which we refer to as our ‘necessary criteria’. We then examine the results of an ‘Unobserved Components’ decomposition and argue that it provides useful information on underlying inflation in Australia. JEL Codes E31, C4 Keywords:Inflation Monetary Policy Time Series Econometrics

Tandem ring-closing metathesis reaction with a ruthenium catalyst containing a N-heterocyclic ligand

The highly active catalyst 2 was used in tandem RCM to make molecules with various ring systems containing α,β-unsaturated carbonyl compounds

Topology of Force Networks in Granular Media under Impact

We investigate the evolution of the force network in experimental systems of two-dimensional granular materials under impact. We use the first Betti number, $\beta_1$, and persistence diagrams, as measures of the topological properties of the force network. We show that the structure of the network has a complex, hysteretic dependence on both the intruder acceleration and the total force response of the granular material. $\beta_1$ can also distinguish between the nonlinear formation and relaxation of the force network. In addition, using the persistence diagram of the force network, we show that the size of the loops in the force network has a Poisson-like distribution, the characteristic size of which changes over the course of the impact

Did Immigrants in the U.S. Labor Market Make Conditions Worse for Native Workers During the Great Recession?

Did the presence of immigrant workers in the United States labor market—including both documented and undocumented workers—significantly affect conditions for low-wage native workers during the Great Recession of 2008-09?�� Building from the methodology developed by Card (2005), our basic finding is straightforward: the presence of immigrants in the U.S. labor market did not contribute in any significant way to the severe labor market problems faced by native workers during the recession. We do emphasize that our conclusion remains provisional until a broader set of data are brought to bear in investigating the question.

Comments on Aaron Yelowitz, "Santa Fe's Living Wage Ordinance and the Labor Market"

In a new study by Yelowitz “Santa Fe’s Wage Ordinance and the Labor Market,” dated September 23, 2005 (published by the Employment Policies Institute) Yelowitz claims to have demonstrated that the Santa Fe living wage ordinance is responsible for significant, negative consequences for Santa Fe’s least educated residents, including a 9.0 percentage point increase in the city’s unemployment rate among such workers. However, he derives these findings through a presentation of evidence that is misleading and incomplete, misusing the available data. We replicate and extend Yelowitz’s model to look at job growth specifically, and, using the same data as Yelowitz, we find that the Santa Fe ordinance did not produce any decline at all in the availability of jobs. Moreover, our estimates suggest that the living wage ordinance did increase earned income for the average worker affected by the ordinance, even if we accept Yelowitz’s estimates on reduced hours of work. In short, even while relying on Yelowitz’s own model and estimates, we find that, to date, the Santa Fe ordinance has succeeded in achieving its main aims: to improve the quality of jobs for low-wage workers in Santa Fe without reducing their employment opportunities.