arXiv subjects

Mirah Gary

Publications and source records attributed to Mirah Gary.

4 recordsLinked to original sources

arXiv2017

The nuts and bolts of the BMS Bootstrap

In this paper, we elaborate on aspects of the recently introduced BMS bootstrap programme. We consider two-dimensional (2d) field theories with BMS3 symmetry and extensively use highest weight representations to uncover the BMS version of crossing symmetry in 4-point functions that are constrained by symmetry. The BMS bootstrap equation is formulated and then analytic expressions for BMS blocks are constructed by looking at the limit of large central charges. These results are also applicable to 2d Galilean Conformal Field Theories through the isomorphism between the BMS3 and 2d Galilean Conformal Algebras. We recover our previously obtained results in the non-relativistic limit of the corresponding ones in 2d relativistic CFTs. This provides a comprehensive check of our previous analysis. We also explore the chiral limit of BMS3 where the BMS algebra reduces to a single copy of the Virasoro algebra and show that our analysis is consistent with earlier work in this direction.

hep-th↗

arXiv2016

The BMS Bootstrap

We initiate a study of the bootstrap programme for field theories with BMS symmetry. Specifically, we look at two-dimensional field theories with BMS3 symmetry and, using highest weight representations, we construct the BMS bootstrap equation by formulating the notion of crossing symmetry in the four-point functions of these field theories. In the limit of large central charges, we find analytic expressions for the BMS blocks that are the basic ingredients for the solution of the bootstrap equation. This constitutes, to the best of our knowledge, the first example of the formulation and significant steps towards the solution of a bootstrap equation in a theory which is not a relativistic conformal field theory.

hep-th↗

arXiv2016

Constraints on a fine-grained AdS/CFT correspondence

For a boundary CFT to give a good approximation to the bulk flat-space S-matrix, a number of conditions need to be satisfied: some of those are investigated here. In particular, one would like to identify an appropriate set of approximate asymptotic scattering states, constructed purely via boundary data. We overview, elaborate, and simplify obstacles encountered with existing proposals for these. Those corresponding to normalizable wavefunctions undergo multiple interactions; we contrast this situation with that needed for a flat-space LSZ treatment. Non-normalizable wavefunctions can have spurious interactions, due either to power-law tails of wavepackets or to their non-normalizable behavior, which obscure S-matrix amplitudes we wish to extract; although in the latter case we show that such gravitational interactions can be finite, as a result of gravitational red shift. We outline an illustrative construction of arbitrary normalizable wavepackets from boundary data, that also yields such spurious interactions. Another set of non-trivial questions regard the form of unitarity relations for the bulk S-matrix, and in particular its normalization and multi-particle cuts. These combined constraints, together with those found earlier on boundary singularity structure needed for bulk momentum conservation and other physical/analytic properties, are a non-trivial collection of obstacles to surmount if a fine-grained S-matrix, as opposed to a coarse-grained construction, is to be defined purely from boundary data.

hep-th↗

arXiv2015

Null warped AdS in higher spin gravity

We equip three-dimensional spin-3 gravity in the principal embedding with a new set of boundary conditions that we call "asymptotically null warped AdS". We find a chiral copy of the Polyakov-Bershadsky algebra as asymptotic symmetry algebra, reminiscent of the situation in topologically massive gravity with strict null warped AdS boundary conditions. We prove the invertibility of the map between zuvielbein and metric variables and construct a global gauge transformation to half of AdS spin-3 gravity in the diagonal embedding. This explains why the theory is chiral and why the Polyakov-Bershadsky algebra arises. We then introduce chemical potentials, derive the entropy, free energy, and the holographic response functions, and conclude with a discussion.

hep-th↗