Above the Law: The Prosecutor\u27s Duty to Seek Justice and the Performance of Substantial Assistance Agreements

We study the gravitational-wave (GW) signatures of clouds of ultralight bosons around black holes (BHs) in binary inspirals. These clouds, which are formed via superradiance instabilities for rapidly rotating BHs, produce distinct effects in the population of BH masses and spins, and, for real fields, a continuous monochromatic GW signal. We show that the presence of a binary companion greatly enriches the dynamical evolution of the system, most remarkably through the existence of resonant transitions between the growing and decaying modes of the cloud (analogous to Rabi oscillations in atomic physics). These resonances have rich phenomenological implications for current and future GW detectors. Notably, the amplitude of the GW signal from the clouds may be reduced, and in many cases terminated, much before the binary merger. The presence of a boson cloud can also be revealed in the GW signal from the binary through the imprint of finite-size effects, such as spin-induced multipole moments and tidal Love numbers. The time dependence of the cloud's energy density during the resonance leads to a sharp feature, or at least attenuation, in the contribution from the finite-size terms to the waveforms. The observation of these effects would constrain the properties of putative ultralight bosons through precision GW data, offering new probes of physics beyond the Standard Model

Coherent chemical kinetics as quantum walks II: Radical-pair reactions in Arabidopsis thaliana

We apply the quantum-walk approach recently proposed in arXiv:quant-ph-1506.04213 to a radical-pair reaction where realistic estimates for the intermediate transition rates are available. The well-known average hitting time from quantum walks can be adopted as a measure of how quickly the reaction occurs and we calculate this for varying degrees of dephasing in the radical pair. The time for the radical pair to react to a product is found to be independent of the amount of dephasing introduced, even in the limit of no dephasing where the transient population dynamics exhibit strong coherent oscillations. This can be seen to arise from the existence of a rate-limiting step in the reaction and we argue that in such examples, a purely classical model based on rate equations can be used for estimating the timescale of the reaction but not necessarily its population dynamics

Foreign Output Shocks and Monetary Policy Regimes in Small Open Economies: A DSGE Evaluation of East Asia

East Asia’s small open economies were hit in varying degrees by the sharp drop in the output of major industrial countries during the global financial and economic crisis of 2008-2009. This highlights the role of monetary policy regimes in cushioning small open economies from adverse external output shocks. To assess the welfare impact of external shocks on key macroeconomic variables under different monetary policy regimes, we numerically solve and calculate the welfare loss function of a dynamic stochastic general equilibrium (DSGE) model. We find that CPI inflation targeting minimizes welfare losses for import-to-GDP ratios from 0.3 to 0.9. However, welfare under the pegged exchange rate regime is almost equivalent to CPI inflation targeting when the import-to-GDP ratio is one while the Taylor-type rule minimizes welfare when the import-to-GDP ratio is 0.1. We calibrate the model and derive welfare implications for eight East Asian small open economies.Trade channel, Import-to-GDP ratio, small open economies, welfare, exchange rate regimes, inflation targeting, Taylor rule, foreign output shock

Foreign Output Shocks and Monetary Policy Regimes in Small Open Economies: A DSGE Evaluation of East Asia

East Asia’s small open economies were hit in varying degrees by the sharp drop in the output of major industrial countries during the global financial and economic crisis of 2008-2009. This highlights the role of monetary policy regimes in cushioning small open economies from adverse external output shocks. To assess the welfare impact of external shocks on key macroeconomic variables under different monetary policy regimes, we numerically solve and calculate the welfare loss function of a dynamic stochastic general equilibrium (DSGE) model. We find that CPI inflation targeting minimizes welfare losses for import-to-GDP ratios from 0.3 to 0.9. However, welfare under the pegged exchange rate regime is almost equivalent to CPI inflation targeting when the import-to-GDP ratio is one while the Taylor-type rule minimizes welfare when the import-to-GDP ratio is 0.1. We calibrate the model and derive welfare implications for eight East Asian small open economies.

Optimization of sharp and viewing-angle-independent structural color

Structural coloration produces some of the most brilliant colors in nature and has many applications. However, the two competing properties of narrow bandwidth and broad viewing angle have not been achieved simultaneously in previous studies. Here, we use numerical optimization to discover geometries where a sharp 7% bandwidth in scattering is achieved, yet the peak wavelength varies less than 1%, and the peak height and peak width vary less than 6% over broad viewing angles (0--90$^\circ$) under a directional illumination. Our model system consists of dipole scatterers arranged into several rings; interference among the scattered waves is optimized to yield the wavelength-selective and angle-insensitive response. Such designs can be useful for the recently proposed transparent displays that are based on wavelength-selective scattering

Modelling the Extreme X-ray Spectrum of IRAS 13224-3809

The extreme NLS1 galaxy IRAS 13224-3809 shows significant variability, frequency depended time lags, and strong Fe K line and Fe L features in the long 2011 XMM-Newton observation. In this work we study the spectral properties of IRAS 13224-3809 in detail, and carry out a series of analyses to probe the nature of the source, focusing in particular on the spectral variability exhibited. The RGS spectrum shows no obvious signatures of absorption by partially ionised material (warm absorbers). We fit the 0.3-10.0 keV spectra with a model that includes relativistic reflection from the inner accretion disc, a standard powerlaw AGN continuum, and a low-temperature (~0.1 keV) blackbody, which may originate in the accretion disc, either as direct or reprocessed thermal emission. We find that the reflection model explains the time-averaged spectrum well, and we also undertake flux-resolved and time-resolved spectral analyses, which provide evidence of gravitational light-bending effects. Additionally, the temperature and flux of the blackbody component are found to follow the $L\propto T^{4}$ relation expected for simple thermal blackbody emission from a constant emitting area, indicating a physical origin for this component.Comment: 12 pages, 7 figures, accepted for publication in MNRA