K-K excitations on AdS_5 x S^5 as N=4 ``primary'' superfields

TL;DR

This paper describes the K-K spectrum of IIB string theory on AdS_5 x S^5 using N=4 superfields in harmonic superspace, linking boundary superconformal field theory polynomials to bulk supergravity representations.

Contribution

It introduces a novel superfield description of the K-K spectrum via gauge singlet polynomials in harmonic superspace, connecting boundary CFT operators to bulk supergravity states.

Findings

Massive K-K representations correspond to polynomial degrees p.

The p=2 polynomial describes the massless graviton multiplet.

Explicit state counts are derived for each polynomial degree.

Abstract

We show that the K-K spectrum of IIB string on AdS_5 x S_5 is described by ``twisted chiral'' N=4 superfields, naturally described in ``harmonic superspace'', obtained by taking suitable gauge singlets polynomials of the D3-brane boundary SU(n) superconformal field theory. To each p-order polynomial is associated a massive K-K short representation with 256 x 1/12 p^2(p^2 -1) states. The p=2 quadratic polynomial corresponds to the ``supercurrent multiplet'' describing the ``massless'' bulk graviton multiplet.