arXiv subjects

Alec E. Barns-Graham

Publications and source records attributed to Alec E. Barns-Graham.

3 recordsLinked to original sources

arXiv2018

A Superconformal Index for HyperKähler Cones

We define an index for $\mathfrak{osp}(4^{*}|4)$ superconformal quantum mechanics on a hyperKähler cone. The index is defined on an equivariant symplectic resolution of the cone, which acts as a regulator. We present evidence that the index does not depend on the choice of resolution parameters and encodes information about the spectrum of (semi-) short representations of the superconformal algebra of the unresolved space. In particular, there are two types of multiplet which can be counted exactly using the index. These correspond to holomorphic functions on the cone and to the generators of the Borel-Moore homology on the resolved space respectively. We calculate the resulting index by localisation for a large class of examples.

hep-th↗

arXiv2017

Twistor description of spinning particles in AdS

The two-twistor formulation of particle mechanics in D-dimensional anti-de Sitter space for D=4,5,7, which linearises invariance under the AdS isometry group Sp(4;K) for K=R,C,H, is generalized to the massless N-extended "spinning particle". The twistor variables are gauge invariant with respect to the initial N local worldline supersymmetries; this simplifies aspects of the quantum theory such as implications of global gauge anomalies. We also give details of the two-supertwistor form of the superparticle, in particular the massive superparticle on AdS_5.

hep-th↗

arXiv2017

Anti-de Sitter particles and manifest (super)isometries

Starting from the classical action for a spin-zero particle in a D-dimensional anti-Sitter (AdS) spacetime, we recover the Breitenlohner-Freedman bound by quantization. For D=4,5,7, and using an Sl(2;K) spinor notation for K=R,C,H, we find a bi-twistor form of the action for which the AdS isometry group is linearly realised, although only for zero mass when D=4,7, in agreement with previous constructions. For zero mass and D=4, the conformal isometry group is linearly realized. We extend these results to the superparticle in the maximally supersymmetric "AdS x S" string/M-theory vacua, showing that quantization yields a 128+128 component supermultiplet. We also extend them to the null string.

hep-th↗