English

Sampling the Graviton Pole and Deprojecting the Swampland

High Energy Physics - Theory 2026-04-17 v1

Abstract

We develop a primal bootstrap framework for effective field theories in the presence of a graviton pole, based on finite-resolution sampling rather than smearing, while also allowing direct control over the number of subtractions. We show that this approach reproduces the known projective bounds obtained from smearing in D6D{\ge}6, while yielding slightly stronger bounds in D=5D{=}5. This method also makes it straightforward to impose linearized unitarity directly and provides an access to the extremal spectra. Applying the method to crossing-symmetric dispersion relations, we derive new non-projective bounds that fix the overall scale of the EFT couplings. In D=5D{=}5, for example, we find that MMP7.8\frac{M}{M_{\rm P}}{\lesssim}7.8, showing that the EFT cutoff cannot be taken parametrically larger than the Planck scale. At the extremal values of the couplings, the spectra exhibit a surprising structure: for projective bounds, they exhibit peaks around quadratic Regge-like trajectories, while for the non-projective bounds they form sharp quadratic bands. In the latter case, the leading coefficients further display an inverse-quadratic dependence on the band number.

Keywords

Cite

@article{arxiv.2604.15235,
  title  = {Sampling the Graviton Pole and Deprojecting the Swampland},
  author = {Guangzhuo Peng and Laurentiu Rodina and Anna Tokareva and Yongjun Xu},
  journal= {arXiv preprint arXiv:2604.15235},
  year   = {2026}
}

Comments

46 pages, 29 figures