Splitting of the ground state manifold of classical Heisenberg spins as couplings are varied

We construct clusters of classical Heisenberg spins with two-spin $\vec{S}_i.\vec{S}_j$-type interactions for which the ground state manifold consists of disconnected pieces. We extend the construction to lattices and couplings for which the ground state manifold splits into an exponentially large number of disconnected pieces at a sharp point as the interaction strengths are varied with respect to each other. In one such lattice we construct, the number of disconnected pieces in the ground state manifold can be counted exactly.Comment: Accepted for publication in Physica A; 6 pages, 4 figure

Juliette: A model of sexual consent

The ‘yes means yes’ model of sexual consent and the political and ethical commitments that underpin this model have three fundamental disadvantages. This position unfairly polices the sexual expression of participants; it demands an unreasonably high standard for defining sexual interaction as consensual; and by denying the body’s capacity for expressing sexual consent this model allows perpetrators of sexual violence to define consent. I argue that a critical examination of Marquis de Sade’s novel Juliette can provide the basis for a model of sexual consent that avoids these problems by refraining from pre-judging the means by which consent is communicated

Geomorphology of the Kaikoura area

The major physiographic units in the Kaikoura area are the Peninsula Block, Beach Ridges and Raised Beaches, Hard Rock Areas and the Alluvial Fans. Erosion of the Seaward Kaikoura Mountains and the transfer of the debris to the sea by fan streams have contributed to coastline pro gradation so that a former offshore island, now called the Kaikoura Peninsula, has been joined to the mainland. On the piedmont alluvial plain between the mountains and the sea Otiran Glacial Stage and Holocene fan deposits have covered up older fan surfaces. Stillstands during the tectonic uplift of the Peninsula Block when marine processes cut shore platforms and also higher stands of interglacial sea levels in the Late Pleistocene have contributed to the development of erosion surfaces. Along the coast beach ridges and raised beaches have developed during post-glacial times

Gamma Ray Bursts -- A radio perspective

Gamma-ray bursts (GRBs) are extremely energetic events at cosmological distances. They provide unique laboratory to investigate fundamental physical processes under extreme conditions. Due to extreme luminosities, GRBs are detectable at very high redshifts and potential tracers of cosmic star formation rate at early epoch. While the launch of {\it Swift} and {\it Fermi} has increased our understanding of GRBs tremendously, many new questions have opened up. Radio observations of GRBs uniquely probe the energetics and environments of the explosion. However, currently only 30\% of the bursts are detected in radio bands. Radio observations with upcoming sensitive telescopes will potentially increase the sample size significantly, and allow one to follow the individual bursts for a much longer duration and be able to answer some of the important issues related to true calorimetry, reverse shock emission and environments around the massive stars exploding as GRBs in the early Universe.Comment: To appear in Advances in Astronomy, special issue "Gamma-Ray Burst in Swift/Fermi Era and Beyond