arXiv subjects

Bernardo Rodrigues

Publications and source records attributed to Bernardo Rodrigues.

2 recordsLinked to original sources

arXiv2016

Switched graphs of some strongly regular graphs related to the symplectic graph

Applying a method of Godsil and McKay \cite{GM} to some graphs related to the symplectic graph, a series of new infinite families of strongly regular graphs with parameters $(2^n\pm2^{(n-1)/2},2^{n-1}\pm2^{(n-1)/2},2^{n-2}\pm2^{(n-3)/2},2^{n-2}\pm2^{(n-1)/2})$ are constructed for any odd $n \geq 5$. The construction is described in terms of geometry of quadric in projective space. The binary linear codes of the switched graphs are $[2^n \mp 2^{\frac{n-1}{2}},n+3,2^{t+1}]_2$-code or $[2^n \mp 2^{\frac{n-1}{2}},n+3,2^{t+2}]_2$-code.

math.CO↗

arXiv2016

Classification of quasi-symmetric 2-(64,24,46) designs of Blokhuis-Haemers type

This paper completes the classification of quasi-symmetric 2-$(64,24,46)$ designs of Blokhuis-Haemers type supported by the dual code $C^{\perp}$ of the binary linear code $C$ spanned by the lines of $AG(3,2^2)$ initiated in \cite{bgr-vdt}. It is shown that $C^{\perp}$ contains exactly 30,264 nonisomorphic quasi-symmetric 2-$(64,24,46)$ designs obtainable from maximal arcs in $AG(2,2^2)$ via the Blokhuis-Haemers construction. The related strongly regular graphs are also discussed.

math.CO↗