Aspects of Holography of Taub-NUT-AdS4

TL;DR

This paper explores the holographic duality of Taub-NUT-AdS4, revealing its interpretation as a non-dissipative superfluid with quantized vortices or a dissipative fluid depending on the treatment of the Misner string, supported by scalar fluctuation analysis.

Contribution

It provides a detailed analysis of the holographic interpretation of Taub-NUT-AdS4, connecting bulk scalar fluctuations to boundary fluid properties and clarifying the role of the Misner string in this context.

Findings

Quantization of scalar modes relates to NUT charge and vorticity flux.

Holographic dual can be a non-dissipative superfluid or a dissipative fluid.

Quasinormal modes form infinite-dimensional non-unitary representations.

Abstract

In this paper we consider aspects of the holographic interpretation of Taub-NUT-AdS$_4$. We review our earlier results which show that TNAdS$_4$ gives rise to a holographic three-dimensional conformal fluid having constant vorticity. We then study the holographic relevance of the Misner string by considering bulk scalar fluctuations. The scalar fluctuations organize naturally into representations of the $SU(2)\times \mathbb{R}$ isometry algebra. If we require the string's invisibility we obtain a Dirac-like quantization relating the frequency of the scalar field modes to the NUT charge. As the latter quantity determines the total vorticity flux of the boundary fluid, we argue that such an assumption allows for a holographic interpretation of TNAdS$_4$ as a {\it non-dissipative} superfluid whose excitations are quantized vortices. Alternatively, if we regard the Misner string as a physical object, as has recently been advocated for thermodynamically, the aforementioned quantization conditions are removed, and we find that TNAdS$_4$ corresponds to a holographic fluid whose dissipative properties are probed as usual by the complex quasinormal modes of the bulk fluctuations. We show that such quasinormal modes are, perhaps surprisingly, organized into infinite-dimensional non-unitary representations of the isometry algebra.