Glow in the Dark Matter: Observing galactic halos with scattered light

We consider the observation of diffuse halos of light around the discs of spiral galaxies, as a probe of the interaction cross section between Dark Matter and photons. Using the galaxy M101 as an example, we show that for a scattering cross section at the level of 10^(-23) x (m/GeV) cm^2 or greater Dark Matter in the halo will scatter light out from the more luminous centre of the disc to larger radii, contributing to an effective increased surface brightness at the edges of the observed area on the sky. This allows us to set an upper limit on the DM-photon cross section using data from the Dragonfly instrument. We then show how to improve this constraint, and the potential for discovery, by combining the radial profile of DM-photon scattering with measurements at multiple wavelengths. Observation of diffuse light presents a new and potentially powerful way to probe the interactions of Dark Matter with photons, which is complimentary to existing searches.Comment: 6 pages, 3 figures: v2 matches version accepted to PRL, with an extended discussion of potential background

The Remittances Framework in Lesotho: Assessment of Policies and Programmes Promoting the Multiplier Effect

This study explored policies and programmes aimed at facilitating remittances inflows through formal channels and leveraging remittances for development in Lesotho. The study also looked into regulations and laws on remittances. In order to answer key questions of this study, semi‐structured questionnaires were administered to 29 institutions, including commercial banks, an asset manager, insurance companies, telecommunication companies, government ministries, parastatals, a research institution, a retailer, a savings and credit cooperative and non-governmental organizations. The gaps revealed by this study can be summarised as: the Deferred Pay Act is the only policy driving officially recorded remittance inflows to Lesotho and which facilitated the creation of remittances‐linked savings product by the banking sector; there are restrictions on remittance outflows for immigrants working in the country, though planned to be eliminated; most of remittances transfer products offered by various institutions suit regular income earners with bank accounts, the adoption of mobile‐phone based transfers adoption is low and the mobile‐phone based transfer products cannot be used to make international transfers; there is lack of adoption of remittances‐linked financial products by financial intermediaries and relevant government ministries; the benefits packaged with the remittances‐ linked savings accounts are less attractive; and most of the remittances services providers are concentrated in urban centres. These findings show there is a need to develop policies and programmes for harnessing remittances for development. This study concluded by suggesting policy options for facilitating remittances inflows through regular channels and promoting positive impact of remittances on development

Moeglin's theorem and Goldie rank polynomials in Cartan type A

We use the theory of finite W-algebras associated to nilpotent orbits in the Lie algebra g = gl_N(C) to give another proof of Moeglin's theorem about completely prime primitive ideals in the enveloping algebra U(g). We also make some new observations about Joseph's Goldie rank polynomials in Cartan type A.Comment: final version; minor changes and some additions to bibliography; 32 page