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Large-scale linear time-periodic dynamical systems, for example, may arise through linearization of a nonlinear system about a given periodic solution (possibly as a consequence of a baseline periodic forcing) with subsequent spatial discretization. The potential need to simulate responses to a wide variety of input profiles (viewed as perturbations off a baseline periodic forcing) creates a potent incentive for effective model reduction strategies applicable to linear time-periodic (\n                    <jats:sc>ltp<\/jats:sc>\n                    ) systems. Classical approaches that take into account the underlying time-periodic system structure often utilize the Floquet transform; however, computation of the Floquet transform is typically intractable for large-order systems. In this paper, we develop the notion of a\n                    <jats:italic>partial Floquet transformation<\/jats:italic>\n                    connected to selected invariant subspaces of a time-varying differential operator associated with the\n                    <jats:sc>ltp<\/jats:sc>\n                    system. We modify and repurpose the\n                    <jats:italic>Dominant Pole Algorithm<\/jats:italic>\n                    of Rommes to identify effective invariant subspaces useful for model reduction. We discuss the construction of associated partial Floquet transformations and time-varying reduction bases with which to produce effective reduced-order\n                    <jats:sc>ltp<\/jats:sc>\n                    models and illustrate the process on a simple time-periodic system.\n                  <\/jats:p>","DOI":"10.1007\/s10444-026-10320-9","type":"journal-article","created":{"date-parts":[[2026,6,26]],"date-time":"2026-06-26T10:44:27Z","timestamp":1782470667000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Partial Floquet transformation and model order reduction of linear time-periodic systems"],"prefix":"10.1007","volume":"52","author":[{"given":"Sam","family":"Bender","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christopher","family":"Beattie","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2026,6,26]]},"reference":[{"key":"10320_CR1","doi-asserted-by":"publisher","unstructured":"Bittanti, S., Lovera, M.: On the zero dynamics of helicopter rotor loads. 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