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arXiv · 2610.36166

The Symbiosis of Vainshtein and Chameleon Screening

Sergi Sirera·Tessa Baker·Clare Burrage·James Hallam·Krishna Naidoo
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Abstract

We present the first study of coexisting Vainshtein and Chameleon screening in cosmic structures. Screening hides fifth forces locally, keeping modified gravity viable. Realistic dark-energy models can activate several mechanisms at once, yet this interplay has been overlooked. We find that (i) the Chameleon resolves the long-standing Galileon void pathology; (ii) it suppresses or eliminates the Vainshtein radius around massive sources; and (iii) the Vainshtein term shrinks the Chameleon's screened core. These effects reshape the observable signatures central to cosmological tests of gravity.

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Sergi Sirera, Tessa Baker, Clare Burrage, James Hallam, Krishna Naidoo. 2026-10-26. The Symbiosis of Vainshtein and Chameleon Screening. https://arxiv.org/abs/2610.36166

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