Bhattacharyya, ArpanArpanBhattacharyyaDas, SauryaSauryaDasHaque, S. ShajidulS. ShajidulHaqueUnderwood, BretBretUnderwood2025-08-312025-08-312020-08-1910.1103/PhysRevResearch.2.0332732-s2.0-85107268662http://repository.iitgn.ac.in/handle/IITG2025/25685We compute the circuit complexity of scalar curvature perturbations on Friedmann-Lemaître-Robertson-Walker cosmological backgrounds with a fixed equation of state w using the language of squeezed vacuum states. Backgrounds that are accelerating and expanding, or decelerating and contracting, exhibit features consistent with chaotic behavior, including linearly growing complexity. Remarkably, we uncover a bound on the growth of complexity for both expanding and contracting backgrounds λ≤2|H|, similar to other bounds proposed independently in the literature. The bound is saturated for expanding backgrounds with an equation of state more negative than w=-5/3, and for contracting backgrounds with an equation of state larger than w=1. For expanding backgrounds that preserve the null energy condition, de Sitter space has the largest rate of growth of complexity, and we find a scrambling time that is similar to other estimates up to order 1 factors.trueArticlehttp://link.aps.org/pdf/10.1103/PhysRevResearch.2.033273August 20205003327348