Abstract
We describe a general construction of strongly regular graphs from the collinearity graph of a finite classical polar spaces of rank at least 3 over a finite field of order q. We show that these graphs are non-isomorphic to the collinearity graphs and have the same parameters. For most of these parameters, the collinearity graphs were the only known examples, and so many of our examples are new.
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Notes
See Lemma 2.3.1 in the Master’s thesis of the author: http://math.ihringer.org/mscthesis/thesis.
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Acknowledgements
I would like to thank Aida Abiad for getting me interested in the topic and answering many of my questions about it. The idea for the described construction was triggered by the switching sets defined by Susan Barwick, Wen-Ai Jackson and Tim Penttila. I would like to thank them for this and for providing me with a preprint of their work.
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Ihringer, F. A switching for all strongly regular collinearity graphs from polar spaces. J Algebr Comb 46, 263–274 (2017). https://doi.org/10.1007/s10801-017-0741-y
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DOI: https://doi.org/10.1007/s10801-017-0741-y