The three-body problem and the Hannay angle

The Hannay angle has been previously studied for a celestial circular restricted three-body system by means of an adiabatic approach. In the present work, three main results are obtained. Firstly, a formal connection between perturbation theory and the Hamiltonian adiabatic approach shows that both lead to the Hannay angle; it is thus emphasised that this effect is already contained in classical celestial mechanics, although not yet defined nor evaluated separately. Secondly, a more general expression of the Hannay angle, valid for an action-dependent potential is given; such a generalised expression takes into account that the restricted three-body problem is a time-dependent, two degrees of freedom problem even when restricted to the circular motion of the test body. Consequently, (some of) the eccentricity terms cannot be neglected {\it a priori}. Thirdly, we present a new numerical estimate for the Earth adiabatically driven by Jupiter. We also point out errors in a previous derivation of the Hannay angle for the circular restricted three-body problem, with an action-independent potential.Comment: 11 pages. Accepted by Nonlinearit

Can Perceived Returns Explain Enrollment Gaps in Postgraduate Education?

To understand students' motives in obtaining postgraduate qualifications, we elicit intentions to pursue postgraduate education and beliefs about its returns in a sample of 1,002 university students. We find large gaps in perceptions about the immediate and later-life benefits of postgraduate education, both between first- and continuing-generation students and within the latter group. Differences in student beliefs about returns can account for 70% of the socioeconomic gaps in intentions to pursue postgraduate studies. We document large differences in students' current undergraduate experiences by socioeconomic background and find these to be predictive of perceived returns to postgraduate education

^{59}Co NMR evidence for charge ordering below T_{CO}\sim 51 K in Na_{0.5}CoO_2

The CoO$_{2}$ layers in sodium-cobaltates Na$_{x}$CoO$_{2}$ may be viewed as a spin $S=1/2$ triangular-lattice doped with charge carriers. The underlying physics of the cobaltates is very similar to that of the high $T_{c}$ cuprates. We will present unequivocal $^{59}$Co NMR evidence that below $T_{CO}\sim51 K$, the insulating ground state of the itinerant antiferromagnet Na$_{0.5}$CoO$_{2}$ ($T_{N}\sim 86 K$) is induced by charge ordering.Comment: Phys. Rev. Lett. 100 (2008), in press. 4 figure

The Impact of the Coronavirus Lockdown on Mental Health: Evidence from the US

The coronavirus outbreak has caused significant disruptions to people’s lives. We exploit variation in lockdown measures across states to document the impact of stay-at-home orders on mental health using real time survey data in the US. We find that the lockdown measures lowered mental health by 0.083 standard deviations. This large negative effect is entirely driven by women. As a result of the lockdown measures, the existing gender gap in mental health has increased by 61%. The negative effect on women’s mental health cannot be explained by an increase in financial worries or caring responsibilities

Inequality in the Impact of the Coronavirus Shock: New Survey Evidence for the UK

Using new UK survey data collected on March 25th 2020, we already find that: 57% of workers engaged in less paid work over the past week than usually. 8% of workers in employment a month ago have already lost their job due to COVID-19. For those still in work, the expected probability of job loss within the next four months is 33%. On average, workers expected to earn 35% less in the next four months compared to usual and expect there is a 49% chance of them having problems paying their bills. These harsh impacts are not evenly distributed across the population; the young, and low income earners have been hit hardest. Workers without paid sick leave beyond the statutory minimum are more likely to go to work with a cold or a fever and also work in close proximity to others

Inequality in the Impact of the Coronavirus Shock: Evidence from Real Time Surveys

We present real time survey evidence from the UK, US and Germany showing that the labor market impacts of COVID-19 differ considerably across countries. Employees in Germany, which has a well-established short-time work scheme, are substantially less likely to be affected by the crisis. Within countries, the impacts are highly unequal and exacerbate existing inequalities. Workers in alternative work arrangements and in occupations in which only a small share of tasks can be done from home are more likely to have reduced their hours, lost their jobs and suffered falls in earnings. Less educated workers and women are more affected by the crisis

Furloughing

Over 9 million jobs were furloughed in the UK during the Coronavirus pandemic. Using real time survey evidence from the UK in April and May, we document which workers were most likely to be furloughed and analyze variation in the terms on which they furl

Geometric phases and anholonomy for a class of chaotic classical systems

Berry's phase may be viewed as arising from the parallel transport of a quantal state around a loop in parameter space. In this Letter, the classical limit of this transport is obtained for a particular class of chaotic systems. It is shown that this ``classical parallel transport'' is anholonomic --- transport around a closed curve in parameter space does not bring a point in phase space back to itself --- and is intimately related to the Robbins-Berry classical two-form.Comment: Revtex, 11 pages, no figures

The co-chaperone p23 controls root development through the modulation of auxin distribution in the Arabidopsis root meristem.

Homologues of the p23 co-chaperone of HSP90 are present in all eukaryotes, suggesting conserved functions for this protein throughout evolution. Although p23 has been extensively studied in animal systems, little is known about its function in plants. In the present study, the functional characterization of the two isoforms of p23 in Arabidopsis thaliana is reported, suggesting a key role of p23 in the regulation of root development. Arabidopsis p23 mutants, for either form, show a short root length phenotype with a reduced meristem length. In the root meristem a low auxin level associated with a smaller auxin gradient was observed. A decrease in the expression levels of PIN FORMED PROTEIN (PIN)1, PIN3, and PIN7, contextually to an inefficient polar localization of PIN1, was detected. Collectively these results suggest that both Arabidopsis p23 isoforms are required for root growth, in particular in the maintenance of the root meristem, where the proteins are located