On the Scalar Spectrum of the Y^{p,q} Manifolds

TL;DR

This paper investigates the full scalar spectrum of Y^{p,q} Sasaki-Einstein manifolds, providing bounds on eigenvalues despite analytical challenges, and explores related deformations and extensions.

Contribution

It offers the first comprehensive analysis of the scalar spectrum on Y^{p,q} manifolds, establishing bounds where exact solutions are infeasible.

Findings

Derived bounds on scalar eigenvalues for Y^{p,q} spaces

Identified analytical obstacles in solving the eigenvalue problem

Explored potential deformations and non-conformal extensions

Abstract

The spectra of supergravity modes in anti de Sitter (AdS) space on a five-sphere endowed with the round metric (which is the simplest 5d Sasaki-Einstein space) has been studied in detail in the past. However for the more general class of cohomogeneity one Sasaki-Einstein metrics on S^2 x S^3, given by the Y^{p, q} class, a complete study of the spectra has not been attempted. Earlier studies on scalar spectrum were restricted to only the first few eigenstates. In this paper we take a step in this direction by analysing the full scalar spectrum on these spaces. However it turns out that finding the exact solution of the corresponding eigenvalue problem in closed form is not feasible since the computation of the eigenvalues of the Laplacian boils down to the analysis of a one-dimensional operator of Heun type, whose spectrum cannot be computed in closed form. However, despite this analytical obstacle, we manage to get both lower and upper bounds on the eigenvalues of the scalar spectrum by comparing the eigenvalue problem with a simpler, solvable system. We also briefly touch upon various other new avenues such as non-commutative and dipole deformations as well as possible non-conformal extensions of these models.