Year: 2026
Type: preprint
Abstract: We propose using supernova microlensing to search for ultracompact minihalos and other extended dark structures seeded by enhanced primordial small-scale power. Unlike conventional microlensing searches, which are often optimized for primordial black holes, cosmological supernovae are sensitive to lenses with physical sizes comparable to their Einstein radii (up to $\sim {\rm pc}\left(M/10^4M_\odot\right)^{1/2}$ scale), opening a qualitatively different region of dark object parameter space. We compute the extended object detection efficiency relative to point lenses. We then show how projected limits on the abundance of ultracompact minihalos can be mapped, in benchmark formation scenarios, onto constraints on the primordial power spectrum. With the Vera C. Rubin Observatory expected to deliver an unprecedented LSST supernova sample, supernova microlensing is poised to become a timely and complementary probe of small-scale structure and the physics of the early Universe.
Source: arXiv (Cornell University)
Institutions: Durham University, University of Pennsylvania
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: G1175115578, G2262748287, G2601397997, G300979063, G3452655474, IPPP (UK National Phenomenology Institute) 2022-2026, G3480869486, G3681454997, Proposal for IPPP (UK National Phenomenology Institute), 2020-2023, G4042783231, G425668148, G5080475149, G5195188938, G6080697404, G6218905885, G6326031618, G7084143925, G855041801, G8709270594, G8888022036
OpenAlex ID: W7211883396