Gravitational Waves and Gamma-Rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A

On 2017 August 17, the gravitational-wave event GW170817 was observed by the Advanced LIGO and Virgo detectors, and the gamma-ray burst (GRB) GRB 170817A was observed independently by the Fermi Gamma-ray Burst Monitor, and the Anti-Coincidence Shield for the Spectrometer for the International Gamma-Ray Astrophysics Laboratory. The probability of the near-simultaneous temporal and spatial observation of GRB 170817A and GW170817 occurring by chance is $5.0\times {10}^{-8}$. We therefore confirm binary neutron star mergers as a progenitor of short GRBs. The association of GW170817 and GRB 170817A provides new insight into fundamental physics and the origin of short GRBs. We use the observed time delay of $(+1.74\pm 0.05)\,{\rm{s}}$ between GRB 170817A and GW170817 to: (i) constrain the difference between the speed of gravity and the speed of light to be between $-3\times {10}^{-15}$ and $+7\times {10}^{-16}$ times the speed of light, (ii) place new bounds on the violation of Lorentz invariance, (iii) present a new test of the equivalence principle by constraining the Shapiro delay between gravitational and electromagnetic radiation. We also use the time delay to constrain the size and bulk Lorentz factor of the region emitting the gamma-rays. GRB 170817A is the closest short GRB with a known distance, but is between 2 and 6 orders of magnitude less energetic than other bursts with measured redshift. A new generation of gamma-ray detectors, and subthreshold searches in existing detectors, will be essential to detect similar short bursts at greater distances. Finally, we predict a joint detection rate for the Fermi Gamma-ray Burst Monitor and the Advanced LIGO and Virgo detectors of 0.1-1.4 per year during the 2018-2019 observing run and 0.3-1.7 per year at design sensitivity

Neoliberalism and the revival of agricultural cooperatives: The case of the coffee sector in Uganda

Agricultural cooperatives have seen a comeback in sub‐Saharan Africa. After the collapse of many weakly performing monopolist organizations during the 1980s and 1990s, strengthened cooperatives have emerged since the 2000s. Scholarly knowledge about the state–cooperative relations in which this “revival” takes place remains poor. Based on new evidence from Uganda's coffee sector, this paper discusses the political economy of Africa's cooperative revival. The authors argue that donors' and African governments' renewed support is framed in largely apolitical terms, which obscures the contested political and economic nature of the revival. In the context of neoliberal restructuring processes, state and non‐state institutional support to democratic economic organizations with substantial redistributional agendas remains insufficient. The political–economic context in Uganda—and potentially elsewhere in Africa—contributes to poor terms of trade for agricultural cooperatives while maintaining significant state control over some cooperative activities to protect the status quo interests of big capital and state elites. These conditions are unlikely to produce a conflict‐free, substantial, and sustained revival of cooperatives, which the new promoters of cooperatives suggest is under way