SciPost Submission Page
Probing the Parameter Space of Axion-Like Particles Using Simulation-Based Inference
by Pooja Bhattacharjee, Christopher Eckner, Gabrijela Zaharijas, Gert Kluge, Giacomo D'Amico
Submission summary
| Authors (as registered SciPost users): | Pooja Bhattacharjee |
| Submission information | |
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| Preprint Link: | https://arxiv.org/abs/2509.20578v2 (pdf) |
| Date accepted: | Feb. 5, 2026 |
| Date submitted: | Jan. 15, 2026, 8:45 a.m. |
| Submitted by: | Pooja Bhattacharjee |
| Submitted to: | SciPost Physics Proceedings |
| Proceedings issue: | The 2nd European AI for Fundamental Physics Conference (EuCAIFCon2025) |
| Ontological classification | |
|---|---|
| Academic field: | Physics |
| Specialties: |
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| Approaches: | Experimental, Computational, Phenomenological, Observational |
Abstract
Axion-like particles (ALPs), hypothetical pseudoscalar particles that couple to photons, are among the most actively investigated candidates for new physics beyond the Standard Model. Their interaction with gamma rays in the presence of astrophysical magnetic fields can leave characteristic, energy-dependent modulations in observed spectra. Capturing such subtle features requires precise statistical inference, but standard likelihood-based methods often fall short when faced with complex models, large number of nuisance parameters and limited analytical tractability. In this work, we investigate the application of simulation-based inference (SBI), specifically Truncated Marginal Neural Ratio Estimation (TMNRE), to constrain ALP parameters using simulated observations from the upcoming Cherenkov Telescope Array Observatory (CTAO). We model the gamma-ray emission from the active galactic nucleus NGC 1275, accounting for photon-ALP mixing, extragalactic background light (EBL) absorption, and the full CTAO instrument response. Leveraging the Swyft framework, we infer posteriors for the ALP mass and coupling strength and demonstrate its potential to extract meaningful constraints on ALPs from future real gamma-ray data with CTAO.
Current status:
Editorial decision:
For Journal SciPost Physics Proceedings: Publish
(status: Editorial decision fixed and (if required) accepted by authors)
Reports on this Submission
Report
thanks a lot for the updated report. I consider my questions to be properly assessed in this new report, and I give my sign off to be published. However, I am somewhat disappointed with the content now that the authors have clarified that they "freeze all of the nuisance parameters" instead of "most of the nuisance parameters" as it was originally written in the manuscript. What remains when assuming that simplification is not really a multidimensional problem, and therefore not so interesting beyond a purely academic context. However, this was the material presented at a conference and, therefore, I think needs to be published in these proceedings, but I leave that decision to the editor's discretion.
Kind regards,
Your referee
Recommendation
Publish (meets expectations and criteria for this Journal)