Młotkowski, Wojciech; Obata, Nobuaki Quadratic embedding constants of fan graphs and graph joins. arXiv:2403.16348 Preprint, arXiv:2403.16348 [math.CO] (2024). MSC: 05C50 05C12 05C76 33C47 BibTeX Cite \textit{W. Młotkowski} and \textit{N. Obata}, ``Quadratic embedding constants of fan graphs and graph joins'', Preprint, arXiv:2403.16348 [math.CO] (2024) Full Text: arXiv OA License
Obata, Nobuaki Complete multipartite graphs of non-QE class. (English) Zbl 07779646 Electron. J. Graph Theory Appl. 11, No. 2, 511-527 (2023). MSC: 05C50 05C12 05C76 PDFBibTeX XMLCite \textit{N. Obata}, Electron. J. Graph Theory Appl. 11, No. 2, 511--527 (2023; Zbl 07779646) Full Text: DOI arXiv
Baskoro, Edy Tri; Obata, Nobuaki A Classification of Graphs through Quadratic Embedding Constants and Clique Graph Insights. arXiv:2311.03342 Preprint, arXiv:2311.03342 [math.CO] (2023). MSC: 05C50 05C12 05C76 BibTeX Cite \textit{E. T. Baskoro} and \textit{N. Obata}, ``A Classification of Graphs through Quadratic Embedding Constants and Clique Graph Insights'', Preprint, arXiv:2311.03342 [math.CO] (2023) Full Text: arXiv OA License
Lou, Zhenzhen; Obata, Nobuaki; Huang, Qiongxiang Quadratic embedding constants of graph joins. (English) Zbl 1497.05158 Graphs Comb. 38, No. 5, Paper No. 161, 22 p. (2022). MSC: 05C50 05C12 05C76 05E30 PDFBibTeX XMLCite \textit{Z. Lou} et al., Graphs Comb. 38, No. 5, Paper No. 161, 22 p. (2022; Zbl 1497.05158) Full Text: DOI arXiv
Obata, Nobuaki Primary Non-QE Graphs on Six Vertices. arXiv:2207.13278 Preprint, arXiv:2207.13278 [math.CO] (2022). MSC: 05C50 05C12 05C76 BibTeX Cite \textit{N. Obata}, ``Primary Non-QE Graphs on Six Vertices'', Preprint, arXiv:2207.13278 [math.CO] (2022) Full Text: DOI arXiv OA License
Baskoro, Edy Tri; Obata, Nobuaki Determining finite connected graphs along the quadratic embedding constants of paths. (English) Zbl 1482.05188 Electron. J. Graph Theory Appl. 9, No. 2, 539-560 (2021). MSC: 05C50 05C12 05C76 05C40 PDFBibTeX XMLCite \textit{E. T. Baskoro} and \textit{N. Obata}, Electron. J. Graph Theory Appl. 9, No. 2, 539--560 (2021; Zbl 1482.05188) Full Text: DOI arXiv
Młotkowski, Wojciech; Obata, Nobuaki On quadratic embedding constants of star product graphs. (English) Zbl 1441.05144 Hokkaido Math. J. 49, No. 1, 129-163 (2020). MSC: 05C50 05C12 05C76 PDFBibTeX XMLCite \textit{W. Młotkowski} and \textit{N. Obata}, Hokkaido Math. J. 49, No. 1, 129--163 (2020; Zbl 1441.05144) Full Text: DOI arXiv Euclid
Obata, Nobuaki; Zakiyyah, Alfi Y. Distance matrices and quadratic embedding of graphs. (English) Zbl 1467.05161 Electron. J. Graph Theory Appl. 6, No. 1, 37-60 (2018). MSC: 05C50 05C12 05C76 PDFBibTeX XMLCite \textit{N. Obata} and \textit{A. Y. Zakiyyah}, Electron. J. Graph Theory Appl. 6, No. 1, 37--60 (2018; Zbl 1467.05161) Full Text: DOI
Obata, Nobuaki Quadratic embedding constants of wheel graphs. (English) Zbl 1470.05104 Interdiscip. Inf. Sci. 23, No. 2, 171-174 (2017). MSC: 05C50 05C40 05B20 05C76 PDFBibTeX XMLCite \textit{N. Obata}, Interdiscip. Inf. Sci. 23, No. 2, 171--174 (2017; Zbl 1470.05104) Full Text: DOI
Obata, Nobuaki Spectral analysis of growing graphs. A quantum probability point of view. (English) Zbl 1366.81005 SpringerBriefs in Mathematical Physics 20. Singapore: Springer (ISBN 978-981-10-3505-0/pbk; 978-981-10-3506-7/ebook). viii, 138 p. (2017). Reviewer: Uwe Franz (Besançon) MSC: 81-02 05-02 05C50 05C76 60F05 46L53 81S25 PDFBibTeX XMLCite \textit{N. Obata}, Spectral analysis of growing graphs. A quantum probability point of view. Singapore: Springer (2017; Zbl 1366.81005) Full Text: DOI
Obata, Nobuaki Quantum probability aspects to lexicographic and strong products of graphs. (English) Zbl 1452.05186 Interdiscip. Inf. Sci. 22, No. 1, 143-146 (2016). MSC: 05D40 05C76 05C30 05C50 81S25 PDFBibTeX XMLCite \textit{N. Obata}, Interdiscip. Inf. Sci. 22, No. 1, 143--146 (2016; Zbl 1452.05186) Full Text: DOI
Hibino, Yuji; Lee, Hun Hee; Obata, Nobuaki Asymptotic spectral distributions of distance-\(k\) graphs of Cartesian product graphs. (English) Zbl 1275.05034 Colloq. Math. 132, No. 1, 35-51 (2013). MSC: 05C50 05C12 05C76 47A10 81S25 PDFBibTeX XMLCite \textit{Y. Hibino} et al., Colloq. Math. 132, No. 1, 35--51 (2013; Zbl 1275.05034) Full Text: DOI arXiv
Obata, Nobuaki Manhattan products of digraphs: characteristic polynomials and examples. (English) Zbl 1252.05129 Ann. Funct. Anal. 3, No. 2, 135-143 (2012). MSC: 05C50 05C76 05C20 47A10 PDFBibTeX XMLCite \textit{N. Obata}, Ann. Funct. Anal. 3, No. 2, 135--143 (2012; Zbl 1252.05129) Full Text: DOI EMIS
Obata, Nobuaki Markov product of positive definite kernels and applications to Q-matrices of graph products. (English) Zbl 1222.05173 Colloq. Math. 122, No. 2, 177-184 (2011). MSC: 05C50 05C12 05C76 43A35 81S25 PDFBibTeX XMLCite \textit{N. Obata}, Colloq. Math. 122, No. 2, 177--184 (2011; Zbl 1222.05173) Full Text: DOI Link