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arXiv · 1204.4441

Comment on `The tan {\theta} theorem with relaxed conditions', by Y. Nakatsukasa

Alexander K. Motovilov
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Abstract

We show that in case of the spectral norm, one of the main results of the recent paper "The tan {\theta} theorem with relaxed conditions", by Yuji Nakatsukasa, published in Linear Algebra and its Applications is a corollary of the tan {\theta} theorem proven in [V.Kostrykin, K.A.Makarov, and A.K.Motovilov, On the existence of solutions to the operator Riccati equation and the tan {\theta} theorem, IEOT 51 (2005), 121-140]. We also give an alternative finite-dimensional matrix formulation of another tan {\theta} theorem proven in [S.Albeverio and A.K.Motovilov, The a priori tan {\theta} theorem for spectral subspaces, IEOT 73 (2012), 413-430].

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Alexander K. Motovilov. 2012-04-19. Comment on `The tan {\theta} theorem with relaxed conditions', by Y. Nakatsukasa. https://arxiv.org/abs/1204.4441

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