Graphs and Combinatorics

, Volume 35, Issue 6, pp 1293–1304 | Cite as

Complex Hadamard Matrices Attached to a 3-Class Nonsymmetric Association Scheme

  • Takuya Ikuta
  • Akihiro MunemasaEmail author
Original Paper


In this paper we classify complex Hadamard matrices contained in the Bose–Mesner algebra of 3-class nonsymmetric association schemes. As a consequence of ourclassification, we have two infinite families and some small examples of complex Hadamard matrices contained in the Bose–Mesner algebra of a self-dual fission of a complete multipartite graph.


Association scheme Complex Hadamard matrix 

Mathematics Subject Classification

05E30 05B30 



This work was supported by JSPS KAKENHI Grant number 17K05155.


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Copyright information

© Springer Japan KK, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Kobe Gakuin UniversityKobeJapan
  2. 2.Tohoku UniversitySendaiJapan

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