On symmetric incidence matrices of projective planes

Autor: Partha Pratim Dey, J. L. Hayden
Rok vydání: 1995
Předmět:
Zdroj: Designs, Codes and Cryptography. 6:179-188
ISSN: 1573-7586
0925-1022
Popis: We investigate the incidence matrix of a finite plane of ordern which admits a (C, L)-transitivityG. The elation groupG affords a generalized Hadamard matrixH=(h ij ) of ordern and an incidence matrix for the plane is completely determined by the matrixR(H)=(R(h ij )), whereR(g) denotes the regular permutation matrix forg∈G. We prove that in the caseR(H) is symmetric thatG is an elementary abelian 2-group or elseG is a nonabelian group andn is a square. Results are obtained in the abelian case linking the roots of the incidence matrixR(H) to the roots of the complex matrix χ(H), χ a nontrivial character ofG.
Databáze: OpenAIRE