,
Florian Funke
,
Simon Jantsch
,
Toghrul Karimov
,
Engel Lefaucheux
,
Joël Ouaknine
,
Amaury Pouly
,
David Purser
,
Markus A. Whiteland
Creative Commons Attribution 3.0 Unported license
We consider reachability in dynamical systems with discrete linear updates, but with fixed digital precision, i.e., such that values of the system are rounded at each step. Given a matrix M ∈ ℚ^{d × d}, an initial vector x ∈ ℚ^{d}, a granularity g ∈ ℚ_+ and a rounding operation [⋅] projecting a vector of ℚ^{d} onto another vector whose every entry is a multiple of g, we are interested in the behaviour of the orbit 𝒪 = ⟨[x], [M[x]],[M[M[x]]],… ⟩, i.e., the trajectory of a linear dynamical system in which the state is rounded after each step. For arbitrary rounding functions with bounded effect, we show that the complexity of deciding point-to-point reachability - whether a given target y ∈ ℚ^{d} belongs to 𝒪 - is PSPACE-complete for hyperbolic systems (when no eigenvalue of M has modulus one). We also establish decidability without any restrictions on eigenvalues for several natural classes of rounding functions.
@InProceedings{baier_et_al:LIPIcs.FSTTCS.2020.36,
author = {Baier, Christel and Funke, Florian and Jantsch, Simon and Karimov, Toghrul and Lefaucheux, Engel and Ouaknine, Jo\"{e}l and Pouly, Amaury and Purser, David and Whiteland, Markus A.},
title = {{Reachability in Dynamical Systems with Rounding}},
booktitle = {40th IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2020)},
pages = {36:1--36:17},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-174-0},
ISSN = {1868-8969},
year = {2020},
volume = {182},
editor = {Saxena, Nitin and Simon, Sunil},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.FSTTCS.2020.36},
URN = {urn:nbn:de:0030-drops-132778},
doi = {10.4230/LIPIcs.FSTTCS.2020.36},
annote = {Keywords: dynamical systems, rounding, reachability}
}