Evolution of Dark Matter Halos and their Radio Emissions

Radio synchrotron emission is expected as a natural by-product of the self-annihilation of super-symmetric dark matter particles. In this work we discuss the general properties of the radio emission expected in a wide range of dark matter halos, from local dwarf spheroidal galaxies to large and distant galaxy clusters with the aim to determine the neutralino dark matter detection prospects of the Square Kilometre Array (SKA). The analysis of the SKA detection of dark matter(DM)-induced radio emission is presented for structures spanning a wide range of masses and redshifts, and we also analyze the limits that the SKA can set on the thermally averaged neutralino annihilation cross-section in the event of non-detection. To this aim, we construct a model of the redshift evolution of the radio emissions of dark matter halos and apply it to generate predicted fluxes from a range of neutralino masses and annihilation channels for the dark matter halos surrounding dwarf galaxies, galaxies and galaxy clusters. Using the available SKA performance predictions and its ability to determine an independent measure of the magnetic field in cosmic structures, we explore both the detailed detection prospects and the upper-bounds that might be placed on the neutralino annihilation cross-section in the event of non-detection. We find that the SKA can access a neutralino parameter space far larger than that of any preceding indirect-detection experiment, also improving on the realistic CTA detection prospects, with the possibility of setting cross-section upper-bounds up to four orders of magnitude below the thermal relic density bound. Additionally, we find that neutralino radio emissions carry redshift-independent signatures of the dominant annihilation channel and of neutralino mass, offering therefore a means to identify such non-thermal emissions within the observing frequency range of the SKA.Comment: 30 pages, 37 figures, submitted to JCA

The limits of market-based governance and accountability - PFI refinancing and the resurgence of the regulatory state

The refinancing of PFI (Private Finance Initiative) projects currently represents one of the most contentious aspects of Public Private Partnership in the UK. The negative publicity associated with UK PFI refinancing deals is associated with two main factors, namely evidence of massive private sector profit making in connection with past refinancing deals, and the ‘failure’ of private sector financiers to share refinancing profits with public sector organisations in line with government recommendations. This paper examines the ongoing ‘dance of non-regulation’ associated with PFI refinancing on the basis of traditional Marxist notions of ‘contradictions of capitalism’. Our analysis commences with the argument that PFI represents a prototypical case of an alliance between finance capital and the state, which has been created with the principal purpose of establishing a new source of profits for the private sector. A Marxist analysis of state-business relationships would predict such an alliance to show tendencies towards instability which could arise from a number of factors. These include, among others, the inherent lack of legitimacy of such an alliance vis a vis established policy goals and the stakeholders associated with them; a lack of a credible regulatory framework which, as a systemic prerequisite of private sector profit making, further exacerbates existing problems of legitimation; and, perhaps most importantly, the potentially self-defeating attempt by capital to maximise gains from the exploitation of the existing alliance without concern for the possibility of a political or regulatory backlash. Examining the recent history of PFI refinancing we find evidence of most of these destabilising tendencies which we expect to trigger calls for a greater regulation of PFI projects in the future

A new Miconia (Melastomatacaeae) from Bolivia, with remarks on angular-branched species in the Andes

A new species of Melastomataceae frorm Bolivia is described, illustrated and placed in a phenetic context within Miconia, a genus of 1000 species and about 2000 published names. Miconia quadrialata is readily distinguished from its Congeners by two-colored leaves and sharply four-angular and winged branchlets. A search for quadrangular-branched miconias revealed that 12 of 15 such species (in four sections), including the new species, occur in cloud forest in the Andes, raising the question of the adaptive significance of quadrangular branchlets

The limits of market-based governance and accountability - PFI refinancing and the resurgence of the regulatory state

The refinancing of PFI (Private Finance Initiative) projects currently represents one of the most contentious aspects of Public Private Partnership in the UK. The negative publicity associated with UK PFI refinancing deals is associated with two main factors, namely evidence of massive private sector profit making in connection with past refinancing deals, and the ‘failure’ of private sector financiers to share refinancing profits with public sector organisations in line with government recommendations. This paper examines the ongoing ‘dance of non-regulation’ associated with PFI refinancing on the basis of traditional Marxist notions of ‘contradictions of capitalism’. Our analysis commences with the argument that PFI represents a prototypical case of an alliance between finance capital and the state, which has been created with the principal purpose of establishing a new source of profits for the private sector. A Marxist analysis of state-business relationships would predict such an alliance to show tendencies towards instability which could arise from a number of factors. These include, among others, the inherent lack of legitimacy of such an alliance vis a vis established policy goals and the stakeholders associated with them; a lack of a credible regulatory framework which, as a systemic prerequisite of private sector profit making, further exacerbates existing problems of legitimation; and, perhaps most importantly, the potentially self-defeating attempt by capital to maximise gains from the exploitation of the existing alliance without concern for the possibility of a political or regulatory backlash. Examining the recent history of PFI refinancing we find evidence of most of these destabilising tendencies which we expect to trigger calls for a greater regulation of PFI projects in the future

Deep H alpha images of interacting galaxies

Gravitational interactions between galaxies are believed to increase star formation activity dramatically, and most of the brightest starburst galaxies show clear signs of recent interactions. However, it is still not known how interaction triggers star formation, nor are there models to relate the type or strength of interaction to the location or amount of star formation. We report on a series of deep H alpha images of interacting and post-interaction galaxies which we took with the purpose of finding the young stars and ionized gas in these objects. We were motivated in part by the hope that by studying the very recently formed stars we could see how the interaction process had affected the star formation. We observed the galaxies through 50 A-wide filters, one on the redshifted H alpha line and one off, and a standard R filter. Depending on the galaxy and conditions, images in the B, V, and I filters were also obtained. The images were recorded with a 4x7 ft. or 17 ft. diameter CCD at the 1-meter telescope of the Wise Observatory in Mitzpe Ramon. The H alpha and continuum images are used, together with observations at other wavelengths, to put together as complete a picture as possible of star formation and interactions in each galaxy. The complete observation set is not yet available for all the galaxies but certain results are already clear. There do not seem to be any correlations between H 1 and H alpha structures. In some H 1 plume galaxies H alpha extensions were seen on the other side of the galaxy from the H 1; in others extensive H alpha filaments have been found but not H 1. The preliminary results agree with the simplest model that interaction-induced star formation will be concentrated in the system center, since that is where the mass ends up

Keep walking? Geographical proximity, religion, and relationship banking

We investigate the geographical proximity of firms to their relationship banks. We find that Islamic banks are more remote to their borrowers. We also find that the probability for a firm to connect to a bank substantially decreases in distance, but that the choice along bank characteristics determines how potent distance is in its impact. If the bank in the vicinity is an Islamic bank, distance plays a more muted role, especially in cities with a high conservative party vote and higher trust in religious institutions. Overall, these findings suggest that the presence of banks with certain characteristics in the vicinity may determine the within-firm and across-firm configurations of observable firm-bank connections. (112 words)

Breakup coupling effects on near-barrier ⁶Li, ⁷Be and ⁸B + ⁵⁸Ni elastic scattering compared

New data for near-barrier 6Li, 7Be and 8B + 58Ni elastic scattering enable a comparison of breakup coupling effects for these loosely-bound projectiles. Coupled Discretised Continuum Channels (CDCC) calculations suggest that the large total reaction cross sections for 8B + 58Ni are dominated by breakup at near-barrier energies, unlike 6Li and 7Be where breakup makes a small contribution. In spite of this, the CDCC calculations show a small coupling influence due to breakup for 8B, in contrast to the situation for 6Li and 7Be. An examination of the S matrices gives a clue to this counter-intuitive behaviour