Tidal disruption events (TDEs) are transient, multiwavelength events in which a star is ripped apart by a supermassive black hole. Observations show that in a small fraction of TDEs, a short-lived, synchrotron emitting jet is produced. We observed the newly discovered TDE AT2022cmc with a slew of radio facilities over the first 100 d after its discovery. The light curve from the Arcminute Microkelvin Imager Large Array radio interferometer shows day-time-scale variability which we attribute to a high brightness temperature emitting region as opposed to scintillation. We measure a brightness temperature of 2 × 1015 K, which is unphysical for synchrotron radiation. We suggest that the measured high brightness temperature is a result of relativistic beaming caused by a jet being launched at velocities close to the speed of light along our line of sight. We infer from day-time-scale variability that the jet associated with AT2022cmc has a relativistic Doppler factor of at least 16, which corresponds to a bulk Lorentz factor of at least 8, if we are observing the jet directly on axis. Such an inference is the first conclusive evidence that the radio emission observed from some TDEs is from relativistic jets because it does not rely on an outflow model. We also compare the first 100 d of radio evolution of AT2022cmc with that of the previous bright relativistic TDE,Swift J1644, and find a remarkable similarity in their evolution....

A record performance metric waveguide grating router (WGR) design with a 200 GHz free spectral range (FSR) capable of resolving sub-GHz resolution spectral features is developed for a fine resolution photonic spectral processor (PSP). The WGR’s FSR was designed to support subchannel add/drop from a superchannel of 1 Tb/s capacity. Due to fabrication imperfections, we introduce phase corrections to the light beams emergingfrom the 250 waveguides of the WGR output using a liquid crystal on silicon (LCoS) phase spatial light modulator (SLM) placed in an imaging configuration. A second LCoS SLM is located at the Fourier plane, for arbitrary spectral amplitude and phase manipulations. The PSP is utilized in multiple system transmission experiments, such as flexible spectral shaping and subcarrier drop demultiplexing with sub-GHz spectral resolution.

As traffic volumes carried by optical networks continue to grow by tens of percent year over year, we are rapidly approaching the capacity limit of the conventional communication band within a single-mode fiber. New measures such as elastic optical networking, spectral extension to multi-bands, and spatial expansion to additional fiber overlays or new fiber types are all being considered as potential solutions, whether near term or far. In this tutorial paper, we survey the photonic switching hardware solutions in support of evolving optical networking solutions enabling capacity expansion based on the proposed approaches. We also suggest how reconfigurable add/drop multiplexing nodes will evolve under these scenarios and gauge their properties and relative cost scalings. We identify that the switching technologies continue to evolve and offer network operators the required flexibility in routing information channels in both the spectral and spatial domains. New wavelength-selective switch designs can now support greater resolution, increased functionality and packing density, as well as operation with multiple input and output ports. Various switching constraints can be applied, such as routing of complete spatial superchannels, in an effort to reduce the network cost and simplify the routing protocols and managed pathway count. However, such constraints also reduce the transport efficiency when the network is only partially loaded, and may incur fragmentation. System tradeoffs between switching granularity and implementation complexity and cost will have to be carefully considered for future high-capacity SDM–WDM optical networks. In this work, we present the first cost comparisons, to our knowledge, of the different approaches in an effort to quantify such tradeoffs.

This paper focuses on the centralization program implemented in Israel in 2004 to analyze whether the administrative subordination of municipalities is an effective policy to deal with problems related to soft-budget constraint of lower level governments. The results consistently show, for different specifications and samples of municipalities, that this program brought a substantial decrease of municipalities’ expenditures (mostly because of decreases in salary payments), and an increase of local property tax collection. Our analysis shows that all of the fiscal impact of the program is due to the appointment of an accountant that reports directly to the central government, a relatively mild form of administrative subordination. In contrast, more intrusive forms of subordination, like the central imposition of a recovery program, do not result in any substantial improvement of municipalities’ fiscal situation. This leads us to conclude that a mild form of administrative subordination

Previous studies showed that the Israeli Ministry of Finance has greater power than finance ministries in most developed countries. The article describes three modes of policy analysis that are used in the Budget Department or on its behalf: in-house work, interministerial committees, and public committees. An examination of the three modes of policy analysis indicates that the major weakness of policy analysis is more evident in the in-house work of the Budget Department, which does not systematically evaluate the expected effects of policy proposals on benefits and costs. The interministerial committees or the public committees do not work according to a fixed methodology, and the quality of their analytical work is therefore arbitrary, depending on the people heading the committee. A tradition of presenting a menu of alternatives to policymakers has not been found in all three modes of policy analysis that were researched here. In addition, the decision rule according to which the

This study investigates the effect of candidates’ expenditure on elections’ results focusing on run-off elections’ data. Our analysis, based on all run-off municipal elections in Israel between 1993 and 2008, shows that candidates’ share of the vote is not substantially affected by their campaign spending. This outcome contradicts recent results showing that, in a developing country where voting is compulsory, campaign expenditures have a significant effect on vote shares. Yet, it is in line with the evidence of earlier studies based on developed countries showing that the effect of campaign spending is limited. This leads us to suggest that campaign spending may be effective in developing countries with consolidating democracies because compulsory voting forces the relative poor population to turn out and vote, and this population is relatively more impressionable by campaign spending on media advertisements.