{"paper":{"title":"Where is tree-level heterotic string theory?","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"hep-th","authors_text":"Leonardo Rastelli, Mathieu Boisvert, Waltraut Knop","submitted_at":"2026-06-08T18:00:01Z","abstract_excerpt":"We continue the tree-level S-matrix bootstrap program for quantum gravity, now in ten-dimensional theories with half-maximal supersymmetry. This setting includes the heterotic string and allows us to test whether the string-like structures found in the maximally supersymmetric bootstrap persist with less supersymmetry and in non-planar gauge sectors. Imposing analyticity, crossing symmetry, unitarity, and Regge boundedness, we constraint weakly coupled UV completions of supergravity and super Yang-Mills. In the gravitational sector, much of the boundary of the allowed region is explained by ex"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2606.09980","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2606.09980/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}