Non-geometric cospectral mates of line graphs with a linear representation

نویسندگان

چکیده

For an incidence geometry $${\mathcal G}= ({\mathcal P}, {\mathcal L}, {\text {I}})$$ with a linear representation T}_2^*({\mathcal K})$$ , we apply WQH switching to construct non-geometric graph $$\Gamma '$$ cospectral the line $$ of G}$$ . As application, show that for $$h \ge 2$$ and $$0< m < h$$ there are strongly regular graphs parameters $$(v, k, \lambda \mu ) = (2^{2\,h} (2^{m+h}+2^m-2^h), 2^h (2^h+1)(2^m-1), (2^{m+1}-3), (2^m-1))$$ which not point partial geometries order $$(s,t,\alpha ((2^h+1)(2^m-1), 2^h-1, 2^m-1)$$

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ژورنال

عنوان ژورنال: Journal of Geometry

سال: 2023

ISSN: ['0047-2468', '1420-8997']

DOI: https://doi.org/10.1007/s00022-023-00672-8