Towards gravity from a matrix integral — the polarised IKKT model

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Abstract

The IKKT matrix model is an example of holography where all spacetime dimensions are emergent. It is a simply a multi-matrix integral but conjectured to non-perturbatively describe type IIB string theory. Being a regular matrix integral, as opposed to path integrals, it is technically very tractable. However, the holographic dictionary remains poorly understood due to conceptual difficulties. In this talk, I will discuss a mass deformation of the original matrix integral, the polarised IKKT model, in which some entries of the dictionary can be established. In particular, I will describe how various large N limits of this model capture different bulk gravity phenomena. These include brane polarisation in the presence of background fluxes, backreaction of the polarised branes into bubbling geometries, and the dissolution of branes into D-instantons through a phase transition.

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