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### Ryota Akiyoshi

**■Affiliation**

Assistant Professor (Non-tenured), Graduate School of Letters (Global COE CARLS), Keio University

**■Research Interests**

My research interests are philosophy of mathematics and mathematical logic (proof theory). Especially, (i) the relationship between Gödel's incompleteness theorems and Hilbert's program, (ii) the meaning of logical constants (type theory), and (iii) proof theory of impredicative subsystems of second-order arithmetic (cut-elimination theorem).

**■Vita**

1April 1999-March 2003: Department of Philosophy, Faculty of Letters, Keio University.

April 2003-March 2005: MA Course, Major in Philosophy and Ethics (Philosophy Course), Graduate School of Letters, Keio University

April 2005-March 2010: Ph.D. Major in Philosophy and Ethics (Philosophy Course), Graduate School of Letters, Keio University

**■Awards**

The Japan Association for Philosophy of Science Research Award (2008)

**■Papers**

Ryota Akiyoshi, "Tait's Conservative Extension Theorem Revisited", to appear in *The Journal of Symbolic Logic*.

Ryota Akiyoshi and Grigori Mints, "An Ordinal-Free Proof of the Cutelimination Theorem for Π^{1}_{1} -CA with ω-rule" (abstract), to appear in *The Bulletin of Symbolic Logic*.

Ryota Akiyoshi and Grigori Mints, "An Ordinal-Free Proof of the Cutelimination Theorem for an Impredicative Subsystem of Π^{1}_{1}-CA with ω-rule", *arXiv*, http://arxiv.org/abs/0904.4742.

Ryota Akiyoshi, "On a Relationship between Godel's Second Incompleteness Theorem and Hilbert's Program", *Annals of the Japan Association for Philosophy of Science*, Vol. 17 pp.13-29, 2009.

Ryota Akiyoshi, "An Ordinal-Free Proof of the Cut-elimination Theorem for a Subsystem of Π^{1}_{1} -Analysis with ω-rule", *RIMS Kokyuroku*, No.1635, pp. 1-13, 2009.

**■Talks**

Invited Talk: "An ordinal-free proof of cut-elimination theorem for Π^{1}_{1}-analysis with ω-rule", *Mathematical Logic Seminar*, Stanford University, November 2008.

Invited Talk: "An ordinal-free proof of the cut-elimination theorem for Π^{1}_{1}-analysis withω-rule", *Seminar in Logic and Philosophy of Mathematics*, Kobe University, February 2009.

"An Ordinal-Free Proof of the Cut-Elimination Theorem for Π^{1}_{1}-CA withω-rule" (with G. Mints), *Eleventh Asian Logic Conference*, June 2009.

"On Tait's Conservative Extension Theorem", *The 40th Conference of Philosophy of Science Japan*, Chuuo University, November 2007.

"The Second Incompleteness Theorem and Hilbert's Program", *The Conference of Japan Association for the Philosophy of Science*, Tottori University, June 2007.