From Sasakian 3-structures to quaternionic geometry

Yoshiyuki Watanabe, Hiroshi Mori

Address. Yoshiyuki Watanabe, Department of Mathematics, Faculty of Science, Toyama University, Toyama 930, JAPAN

Hiroshi Mori, Department of Mathematics, Joeteu University of Education, Joetsu, Niigata Pref. 943, JAPAN

E-mail: mori@juen.ac.jp

ywatnabe@sci.toyama-u.ac.jp

Abstract. We construct a family of almost quaternionic Hermitian structures from an almost contact metric 3-structure and also do three kinds of quaternionic Kahler structures from a Sasakian 3-structure. In particular we have a generalization of the second main result of Boyer-Galicki-Mann [5].

AMSclassification. 53C25, 53C15

Keywords. almost contact metric 3-structure, Sasakian 3-structure, almost quaternionic Hermitian manifold, quaternionic Kahler manifold, hyperkahler manifold