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1) Negations and Meets in Topos Quantum Theory, Foundations of Physics, Vol. 52, No. 1, Article number: 12, Dec 2021.2) A State-Dependent Noncontextuality Inequality in Algebraic Quantum Theory, Physics Letters A, Vol. 381, No. 29,2305-2312, May 2017.3) Characterizing Common Cause Closedness of Quantum Probability Theories, Studies in History and Philosophy of Modern Physics, Vol. 52, 234-241, Nov 2015.4) EPR states and Bell Correlated States in Algebraic Quantum Field Theory, Foundations of Physics, Vol. 43, No. 10, 1182-1192, Oct 20135) Reconstructing Bohr's reply to EPR in Algebraic Quantum Theory, Foundations of Physics, Vol. 42, No. 4, 475-487, Feb 2012.Yuichiro Kitajima is a professor at the Department of Liberal Arts and Basic Sciences, College of Industrial Technology, Nihon University. He received his B.A. in Nuclear Engineering from Kyoto University in 1997, his M.S. in Nuclear Engineering from Kyoto University in 2001, and his Ph.D. from Hokkaido University in 2005. He studied at the Graduate School of Letters, Kyoto University from 2007 to 2010 under a Research Fellowship for Young Scientists, and at the Department of Philosophy, Princeton University in 2008 as a visiting postdoctoral research associate. He has been studying reality and locality in quantum theory focusing on the argument related to reality and locality in quantum mechanics by Einstein-Podolsky-Rosen. They concluded that quantum mechanics is incomplete on the assumption that the measurement of one particle does not affect the element of reality of another particle that is spatially distant from that particle. Bohr, on the other hand, disagreed with the assumption and concluded that quantum mechanics is complete. In other words, the difference between Einstein-Podolsky-Rosen’s and Bohr’s views on the completeness of quantum mechanics stems from whether the measurement of one particle affects the element of reality of another particle that is spatially distant from that particle. Dr. Kitajima attempted to clarify the objection by Bohr and examined what Bohr’s element of reality would be under the conditions that Bohr seems to assume implicitly. With regard to locality in quantum theory, he also noted the Einstein-Podolsky-Rosen argument. The states they used in their discussion are called EPR states, which have properties that do not appear in the classical world. One such property is called Bell’s inequality violation, and it is known that Bell’s inequality cannot be violated in the classical world, but it can be violated in the quantum world. However, the logical relationship between the Einstein-Podolsky-Rosen argument and Bell inequality violation was not clear. Dr. Kitajima showed that Bell’s inequalities are always violated in states where the Einstein-Podolsky-Rosen argument holds. Dr. Kitajima has also studied the contextuality in quantum theory, which concerns reality. In the classical world, measurement results are independent of the context of the measurement. For example, when measuring the length of a pencil, the measurement result is the same whether the pencil’s color or hardness is measured at the same time. In contrast, in quantum theory, the measurement result can be different depending on the context of the measurement. Dr. Kitajima studied an inequality called the KCBS inequality, which is related to contextuality in quantum theory.－　　－38Research AchievementsYuichiro KITAJIMAProfessor, Department of Liberal Arts and Basic Sciences