The automorphism group of $$NU(3,q^2)$$

Abstract Let $$H(n, q^2)$$ H ( n , q 2 ) be a non-degenerate Hermitian variety of $$PG(n,q^2)$$ P G , $$n \ge 2$$ ≥ . $$NU(n+1,q^2)$$ N U + 1 the graph whose vertices are points $$PG(n,q^2) \setminus H(n,q^2)$$ \ and two u v adjacent if line joining is tangent to q^2 )$$ Then $$NU(n + 1, strongly regular graph. In this paper we show that automorphism group $$NU(3,q^2)$$ 3 isomorphic either $$P\Gamma U(3,q)$$ Γ projective unitary PGU (3, q ), or $$S_{3} \wr S_4$$ S ≀ 4 according as $$q \ne ≠ $$q=2$$ =