TY - JOUR ID - 44746 TI - Operators Reversing Orthogonality and Characterization of Inner Product Spaces JO - Khayyam Journal of Mathematics JA - KJM LA - en SN - AU - Wójcik, Paweł AD - Institute of Mathematics, Pedagogical University of Cracow, Podchorążych 2, 30-084 Kraków, Poland. Y1 - 2017 PY - 2017 VL - 3 IS - 1 SP - 22 EP - 24 KW - Birkhoff orthogonality KW - orthogonality reversing mappings KW - characterizations of inner product spaces DO - 10.22034/kjm.2017.44746 N2 - In this short paper we answer a question posed by Chmieliński in [Adv. Oper. Theory, 1 (2016), no. 1, 8-14]. Namely, we prove that among normed spaces of dimension greater than two,only inner product spaces admit nonzero linear operators which reverse the Birkhoff orthogonality. UR - https://www.kjm-math.org/article_44746.html L1 - https://www.kjm-math.org/article_44746_9f829bbb7fc2df9483fd2622f9084732.pdf ER -