to be warped product manifolds S. Kazan and B. Sahin Received: October 30, 2012; Accepted: May 7, 2013 Abstract. In this paper, we give characterizations for a twisted product manifold to be a warped product manifold by imposing certain conditions on Weyl conformal curvature tensor and Weyl projective tensor. We also find similar results for multiply twisted product manifolds. Keywords: twisted product; warped product; Ricci curvature tensor; Weyl curvature tensor AMS Subject classification: Primary: 53C50, 53C42 Version to read: PDF ISSN 0862-9544 (Printed edition) Faculty of Mathematics, Physics and Informatics Comenius University 842 48 Bratislava, Slovak Republic Telephone: + 421-2-60295111 Fax: + 421-2-65425882 e-Mail: amuc@fmph.uniba.sk Internet: www.iam.fmph.uniba.sk/amuc © 2013, ACTA MATHEMATICA UNIVERSITATIS COMENIANAE |