Molecular dynamics simulations are used to study hypervelocity impacts of an ultrathin flyer plate with a semi-infinite two-dimensional model diatomic molecular solid. These hypervelocity impacts are shown to produce a dissociative phase transition from a molecular to a close-packed solid in the target material. Although this close-packed phase persists for less than 10 picoseconds and is confi...

We describe representations of certain superconformal algebras in the semi-infinite Weil complex related to the loop algebra of a complex finite-dimensional Lie algebra and in the semi-infinite cohomology. We show that in the case where the Lie algebra is endowed with a nondegenerate invariant symmetric bilinear form, the relative semi-infinite cohomology of the loop algebra has a structure, wh...