横山 啓太 （ヨコヤマ ケイタ） 助教
- 1. Caristi's fixed point theorem in reverse mathematic，Keita Yokoyama，Twelfth International Conference on Computability, Complexity and Randomness (CCR 2017), Mysore, India, 3-7 July, 2017.
- 2. On the first-order strength of Ramsey's theorem in reverse mathematics，Keita Yokoyama，Logic Colloquium 2017, Special session on computability, Stockholm University, Sweden, August 14-20, 2017.
- 3. On the first-order part of Ramsey's theorem for pairs，Keita Yokoyama，Computability Theory and Foundations of Mathematics 2017, September 11, 2017.
- 4. Indicator arguments and the strength of Ramsey's theorem,，Keita Yokoyama，Logic seminar, University of Leeds, February 1, UK, 2017.
- 5. On the first-order strength of Ramsey's theorem for pairs，Keita Yokoyama，Logic seminar, University of Warsaw, February 8, 2017.
- 6. Ramsey's theorem and the size of proofs in arithmetic，Keita Yokoyama，Logic seminar, University of Pennsylvania, April 22, 2017.
- 7. Reverse mathematics and basic analysis，横山啓太，第4回山陰基礎論・解析学研究集会, 国際ファミリープラザ, 米子, 2017年1月8日.
- 8. Indicator and the length of the proof in arithmetic，横山啓太，ラムダ計算と論理の早春セミナー, 草津セミナーハウス, 2017年3月17日.
- 9. Konig's lemma for a tree which has at most finitely many paths in reverse mathematics，横山啓太，日本数学会, 首都大学東京, 2017年3月24日.
- 10. The proof-theoretic strength of Ramsey's theorem for pairs，Keita Yokoyama，New Challenges in Reverse Mathematics, National University of Singapore, January 3-16, 2016.
- 11. Thoughts on indicators and density notions，Keita Yokoyama，IMS-JSPS Joint Workshop on Mathematical Logic and the Foundations of Mathematics, National University of Singapore, January 15-16, 2016.
- 12. Nonstandard methods in combinatorics，Keita Yokoyama，The 11th AIMS Conference on Dynamical Systems, Differential Equations and Applications, Special session: Nonstandard Analysis, Quantizations and Singular Perturbations, Orlando, Florida, USA, July 4, 2016.
- 13. On the Proof-Theoretic Strength of Ramsey's Theorem for Pairs，Keita Yokoyama，Mathematical Logic and Its Applications, RIMS, Kyoto University, Kyoto, Japan, September 26-29, 2016.
- 14. The proof-theoretic strength of Ramsey's theorem for pairs，Keita Yokoyama，Mathematics for Computation, Lower Bavaria, DE, Germany, May 8-13, 2016.
- 15. On the first-order strength of Ramsey's theorem for pairs and finitely many colors，Theodore A. Slaman and Keita Yokoyama，Association for Symbolic Logic 2016 Annual North American Meeting, University of Connecticut, Storrs, USA, May 23-26, 2016.
- 16. Proof-theoretic strength and indicator arguments，Keita Yokoyama，Workshop on Mathematical Logic and its Applications, JSPS Core-to-Core Program, Kyoto University, Kyoto, Japan, September 16-17, 2016.
- 17. Trees with at most finitely many paths in reverse mathematics，Keita Yokoyama，Computability Theory and Foundations of Mathematics 2016, Waseda University, Tokyo, Japan, September 20-21, 2016.
- 18. On the proof-theoretic strength of Ramsey's theorem for pairs，横山啓太，日本数学会, 関西大学, 2016年9月18日.
- 19. The proof-theoretic strength of Ramsey's theorem for pairs and two colors，Keita Yokoyama，KGRC seminar, Kurt Godel Research Center, University of Vienna, Austria, February 11, 2016.
- 20. On the proof-theoretic strength of Ramsey’s theorem for pairs，Keita Yokoyama，Logic seminar, Vanderbilt University, USA, July 7, 2016.