Type IIB Axion--Dilaton Wormholes and the BPS Limit Hessian

I revisit Type-IIB axion--dilaton Euclidean saddles in a specified axion charge sector. In that sector, the solution with $E=0$ is the BPS instanton, while $E>0$ gives non-BPS wormholes with a smooth throat. The two cases solve the same radial equations but define different fluctuation problems. For the $E=0$ instanton, the Hamiltonian constraint, gauge quotient, charge-sector boundary condition, and removal of collective zero modes reduce the quadratic action to a physical Hessian. This Hessian factorizes, ${\cal H}_ν={\mathcal Q}_ν^\dagger{\mathcal Q}_ν$. I interpret this as an endpoint theorem, beyond a stability theorem for the full $E>0$ wormhole. This puts Type IIB wormhole spectra on firmer grounds. I also separate the connected two-ended wormhole throat from its long-distance two-end multipole operator term. Once the coefficient matrix $C^{ij}$ is derived, the different-component and same-component placements of the two end insertions are terms in the same quadratic expression. Removing either term requires a genuine projection or cancellation.

Source: arXiv:2607.01221v1 - http://arxiv.org/abs/2607.01221v1 PDF: https://arxiv.org/pdf/2607.01221v1 Original Link: http://arxiv.org/abs/2607.01221v1