Book review: a tale of two books: digital transformations are creeping across the face of academic life

In response to Patrick Dunleavy’s posts on the future of e-publishing in academia, David Gauntlett writes on his experiences of publishing ebooks, and how Kindle self-publishing could be an approach which gets books to readers at a far more affordable price, as well as being surprisingly better for authors too

Using Creative Visual Research Methods to Understand Media Audiences

This article introduces an emerging area of qualitative media «audience» research, in which individuals are asked to produce media or visual material themselves, as a way of exploring their relationship with particular issues or dimensions of media. The process of making a creative visual artefact – as well as the artefact itself (which may be, for example, a video, drawing, collage, or imagined magazine cover) – offers a reflective entry-point into an exploration of individuals» relationships with media culture. This article sets out some of the origins, rationale and philosophy underlying this methodological approach; briefly discusses two example studies (one in which children made videos to consider their relationship with the environment, and one in which young people drew pictures of celebrities as part of an examination of their aspirations and identifications with stars); and finally considers some emerging issues for further development of this method

Dyons and S-Duality in N=4 Supersymmetric Gauge Theory

We analyze the spectrum of dyons in N=4 supersymmetric Yang-Mills theory with gauge group SU(3) spontaneously broken down to U(1)xU(1). The Higgs fields select a natural basis of simple roots. Acting with S-duality on the W-boson states corresponding to simple roots leads to an orbit of BPS dyon states that are magnetically charged with respect to one of the U(1)'s. The corresponding monopole solutions can be obtained by embedding SU(2) monopoles into SU(3) and the S-duality predictions reduce to the SU(2) case. Acting with S-duality on the W-boson corresponding to a non-simple root leads to an infinite set of new S-duality predictions. The simplest of these corresponds to the existence of a harmonic form on the moduli space of SU(3) monopoles that have magnetic charge (1,1) with respect to the two U(1)'s. We argue that the moduli space is given by R^3x(R^1xM)/Z_2, where M is Euclidean Taub-NUT space, and that the latter admits the appropriate normalizable harmonic two form. We briefly discuss the generalizations to other gauge groups.Comment: 13 pages (Harvmac b), discrete identification corrected, reference adde

A supersymmetric black ring

A new supersymmetric black hole solution of five-dimensional supergravity is presented. It has an event horizon of topology S1xS2. This is the first example of a supersymmetric, asymptotically flat black hole of non-spherical topology. The solution is uniquely specified by its electric charge and two independent angular momenta. These conserved charges can be arbitrarily close, but not exactly equal, to those of a supersymmetric black hole of spherical topology.Comment: 4 pages, 1 figure. v2: Comment about chiral null models remove

A Note on 1/4-BPS States

We study classical solutions of N=4 super Yang-Mills theories that are invariant under 1/4 of the supersymmetry generators. Expressions for the mass and electric charge of the configurations are derived as functions on the monopole moduli space. These functions also provide a method of determining the number of normalisable bosonic zero modes.Comment: 10 pages, LaTe

Vortex Strings and Four-Dimensional Gauge Dynamics

We study the low-energy quantum dynamics of vortex strings in the Higgs phase of N=2 supersymmetric QCD. The exact BPS spectrum of the stretched string is shown to coincide with the BPS spectrum of the four-dimensional parent gauge theory. Perturbative string excitations correspond to bound W-bosons and quarks while the monopoles appear as kinks on the vortex string. This provides a physical explanation for an observation by N. Dorey relating the quantum spectra of theories in two and four dimensions.Comment: 23 pages, 1 figure. v2: Two extra appendices included: one on the brane construction, the other describing the potential on the vortex moduli space. Two figures added. Typos corrected and references added. v3: BPS nature of quarks correcte

Supersymmetric black rings and three-charge supertubes

We present supergravity solutions for 1/8-supersymmetric black supertubes with three charges and three dipoles. Their reduction to five dimensions yields supersymmetric black rings with regular horizons and two independent angular momenta. The general solution contains seven independent parameters and provides the first example of non-uniqueness of supersymmetric black holes. In ten dimensions, the solutions can be realized as D1-D5-P black supertubes. We also present a worldvolume construction of a supertube that exhibits three dipoles explicitly. This description allows an arbitrary cross-section but captures only one of the angular momenta.Comment: 59 pages, 6 figures; v2: minor correction

Non-commutative vs. Commutative Descriptions of D-brane BIons

The U(1) gauge theory on a D3-brane with non-commutative worldvolume is shown to admit BIon-like solutions which saturate a BPS bound on the energy. The mapping of these solutions to ordinary fields is found exactly, namely non-perturbatively in the non-commutativity parameters. The result is precisely an ordinary supersymmetric BIon in the presence of a background B-field. We argue that the result provides evidence in favour of the exact equivalence of the non-commutative and the ordinary descriptions of D-branes.Comment: 1+15 pages, 6 figures; v2: two references added, typos corrected, one unnecessary figure remove

Brane-Intersection Dynamics from Branes in Brane Backgrounds

We derive the dynamics of M-brane intersections from the worldvolume action of one brane in the background supergravity solution of another one. In this way we obtain an effective action for the self-dual string boundary of an M2-brane in an M5-brane, and show that the dynamics of the 3-brane intersection of two M5-branes is described by a Dirac-Born-Infeld action.Comment: 12 pages,latex. Typos corrected, reference adde

D-brane Solitons in Supersymmetric Sigma-Models

Massive D=4 N=2 supersymmetric sigma models typically admit domain wall (Q-kink) solutions and string (Q-lump) solutions, both preserving 1/2 supersymmetry. We exhibit a new static 1/4 supersymmetric `kink-lump' solution in which a string ends on a wall, and show that it has an effective realization as a BIon of the D=4 super DBI-action. It is also shown to have a time-dependent Q-kink-lump generalization which reduces to the Q-lump in a limit corresponding to infinite BI magnetic field. All these 1/4 supersymmetric sigma-model solitons are shown to be realized in M-theory as calibrated, or `Q-calibrated', M5-branes in an M-monopole background.Comment: 16 pages, 3 figures, Late