Loop Blow-up Inflation: An Overview

[2604.07288] Loop Blow-up Inflation: An Overview Skip to main content Search Submit Donate Log in High Energy Physics - Theory arXiv:2604.07288 (hep-th) [Submitted on 8 Apr 2026 ( v1 ), last revised 25 Jun 2026 (this version, v2)] Title: Loop Blow-up Inflation: An Overview Authors: Sukŗti Bansal View PDF HTML (experimental) Abstract: This proceedings contribution provides an overview of Loop Blow-up Inflation and updates its observational predictions and their comparison with the latest CMB and BAO data. It is based on work originally published in arXiv:2403.04831 , done in collaboration with L. Brunelli, M. Cicoli, A. Hebecker, and R. Kuespert, and presented at the 2025 Workshop on Quantum Gravity and Strings. We focus on string loop corrections to the Kähler potential, long regarded as a potential threat to blow-up inflation in the Large Volume Scenario. We argue that these corrections, previously assumed avoidable, are generically present and qualitatively alter the original non-perturbative picture: they invalidate slow-roll near the minimum and instead generate a new slow-roll regime at larger field values, where the scalar potential transitions from an exponential to a power-law plateau. This leads to modified inflationary dynamics and distinct cosmological predictions, including an increased tensor-to-scalar ratio. For the scenario with vanishing extra dark radiation, we compare with the latest combined analyses of ACT, DESI, SPT, BICEP/Keck, and Planck, while for scenarios with non-zero extra dark radiation we use ACT DR6 constraints. Tighter observational bounds on extra dark radiation require updated model parameters in one scenario, yielding revised predictions presented here for the first time. All predictions remain consistent with recent observations, with the ACT+DESI combination yielding near-perfect agreement in the spectral index for vanishing extra dark radiation, with a deviation of $0.03\sigma$. We also comment on subleading loop corrections, which improve robustness by reducing the field value required for slow roll. These results highlight that string loop effects, rather than being merely detrimental, can play a constructive role in realising viable inflation in string compactifications. Comments: 15 pages, 2 figures. Contribution to Proceedings of Science (PoS): Corfu Summer Institute 2025 - Workshop on Quantum Gravity and Strings; v2: minor improvements in a few explanations Subjects: High Energy Physics - Theory (hep-th) ; Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc) Cite as: arXiv:2604.07288 [hep-th] (or arXiv:2604.07288v2 [hep-th] for this version) https://doi.org/10.48550/arXiv.2604.07288 Focus to learn more arXiv-issued DOI via DataCite Journal reference: PoS CORFU2025 (2026) 310 Related DOI : https://doi.org/10.22323/1.509.0310 Focus to learn more DOI(s) linking to related resources Submission history From: Sukŗti Bansal [ view email ] [v1] Wed, 8 Apr 2026 16:53:11 UTC (165 KB) [v2] Thu, 25 Jun 2026 21:44:25 UTC (165 KB) Full-text links: Access Paper: View PDF HTML (experimental) TeX Source view license Current browse context: hep-th < prev | next > new | recent | 2026-04 Change to browse by: astro-ph astro-ph.CO gr-qc References & Citations INSPIRE HEP SciX Google Scholar Semantic Scholar export BibTeX citation Bookmark Bibliographic Tools Bibliographic and Citation Tools Bibliographic Explorer Toggle Bibliographic Explorer ( What is the Explorer? ) Connected Papers Toggle Connected Papers ( What is Connected Papers? ) Litmaps Toggle Litmaps ( What is Litmaps? ) scite.ai Toggle scite Smart Citations ( What are Smart Citations? ) Code, Data, Media Code, Data and Media Associated with this Article alphaXiv Toggle alphaXiv ( What is alphaXiv? ) Links to Code Toggle CatalyzeX Code Finder for Papers ( What is CatalyzeX? ) DagsHub Toggle DagsHub ( What is DagsHub? ) GotitPub Toggle Gotit.pub ( What is GotitPub? ) Huggingface Toggle Hugging Face ( What is Huggingface? ) ScienceCast Toggle ScienceCast ( What is ScienceCast? ) Demos Demos Replicate Toggle Replicate ( What is Replicate? ) Spaces Toggle Hugging Face Spaces ( What is Spaces? ) Spaces Toggle TXYZ.AI ( What is TXYZ.AI? ) Related Papers Recommenders and Search Tools Link to Influence Flower Influence Flower ( What are Influence Flowers? ) Core recommender toggle CORE Recommender ( What is CORE? ) IArxiv recommender toggle IArxiv Recommender ( What is IArxiv? ) Author Venue Institution Topic About arXivLabs arXivLabs: experimental projects with community collaborators arXivLabs is a framework that allows collaborators to develop and share new arXiv features directly on our website. 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