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Godsil–McKay switching and twisted Grassmann graphs

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Abstract

We show that the twisted Grassmann graphs introduced by Van Dam and Koolen are obtained by Godsil–McKay switching applied to the Grassmann graphs. The partition for the switching is constructed by a polarity of a hyperplane.

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Acknowledgments

The author would like to thank Alexander Gavrilyuk for helpful discussions.

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Authors and Affiliations

  1. Research Center for Pure and Applied Mathematics, Graduate School of Information Sciences, Tohoku University, Sendai, Japan

    Akihiro Munemasa

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  1. Akihiro Munemasa
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Correspondence to Akihiro Munemasa.

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Dedicated to Andries E. Brouwer on the occasion of his 65th birthday.

This is one of several papers published in Designs, Codes and Cryptography comprising the special issue in honor of Andries Brouwer’s 65th birthday.

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Munemasa, A. Godsil–McKay switching and twisted Grassmann graphs. Des. Codes Cryptogr. 84, 173–179 (2017). https://doi.org/10.1007/s10623-016-0244-1

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  • DOI: https://doi.org/10.1007/s10623-016-0244-1

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