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Aspects of computability-theoretic structures as topological invariants

Research Project

Project/Area Number 17H06738
Research Category

Grant-in-Aid for Research Activity Start-up

Allocation TypeSingle-year Grants
Research Field Foundations of mathematics/Applied mathematics
Research InstitutionNagoya University

Principal Investigator

Takayuki Kihara  名古屋大学, 情報学研究科, 講師 (80722701)

Project Period (FY) 2017-08-25 – 2019-03-31
Project Status Completed (Fiscal Year 2018)
Budget Amount *help
¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2017: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Keywords計算可能性理論 / 記述集合論 / 逆数学 / 計算可能解析学 / 再帰理論 / コルモゴロフ複雑性 / 位相次元論 / フラクタル次元 / 高階関数 / 一般位相空間論 / 構成可能宇宙 / 領域理論 / 高階計算 / 決定性公理 / Weihrauch次数 / 数学基礎論
Outline of Final Research Achievements

By analyzing computability-theoretic structures from the topological viewpoint, we obtained a large number of results on the relationship among computability theory, descriptive set theory, and general topology. Most of results concern on extracting the computability theoretic nature from topological structures and set-theoretic structures, and then clarify these structures.
For example, by understanding the principle of computable enumerations as some sorts of nonmetrizable topology, we established a new theory unifying the previous works on enumeration degrees. For another example, applying computability theory on uncountable cardinals, we succeeded to obtain a complete description of the bqo-valued Borel functions on nonseparable complete ultrametric spaces. Furthermore, we also solved several open problems, e.g., in reverse mathematics.

Academic Significance and Societal Importance of the Research Achievements

計算可能性の理論は,コンピュータ科学の理論的基礎を支えるものである.本研究は,『空間』『次元』『ランダム性』といった素朴で重要な数学的構造が内部に孕む計算論的構造を明示化するという点で意義深い.また,このような発想は,逆に,非計算論的数学の概念を用いた計算論的概念の再理解にも繋がる.したがって,報告者の手法の応用範囲の拡大は,計算論と応用対象の分野双方に新たな手法と視点を持ち込むこととなり,広範な分野にインパクトを与えるものとなる.

Report

(3 results)
  • 2018 Annual Research Report   Final Research Report ( PDF )
  • 2017 Annual Research Report
  • Research Products

    (28 results)

All 2019 2018 2017 Other

All Int'l Joint Research (6 results) Journal Article (6 results) (of which Int'l Joint Research: 5 results,  Peer Reviewed: 6 results) Presentation (14 results) (of which Int'l Joint Research: 12 results,  Invited: 9 results) Remarks (2 results)

  • [Int'l Joint Research] Swansea University(英国)

    • Related Report
      2018 Annual Research Report
  • [Int'l Joint Research] Universite Paris-Est Creteil(フランス)

    • Related Report
      2018 Annual Research Report
  • [Int'l Joint Research] Nangyang Technological University(シンガポール)

    • Related Report
      2018 Annual Research Report
  • [Int'l Joint Research] University of Udine/University of Turin(Italy)

    • Related Report
      2017 Annual Research Report
  • [Int'l Joint Research] Swansea University(United Kingdom)

    • Related Report
      2017 Annual Research Report
  • [Int'l Joint Research] University of California, Berkeley/University of Connecticut(米国)

    • Related Report
      2017 Annual Research Report
  • [Journal Article] On the structure of the Wadge degrees of bqo-valued Borel functions2019

    • Author(s)
      Takayuki Kihara, and Antonio Montalban
    • Journal Title

      Transactions of the American Mathematical Society

      Volume: 371 Issue: 11 Pages: 7885-7923

    • DOI

      10.1090/tran/7621

    • Related Report
      2018 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] On a metric generalization of the tt-degrees and effective dimension theory2019

    • Author(s)
      Takayuki Kihara
    • Journal Title

      The Journal of Symbolic Logic

      Volume: 印刷中 Issue: 02 Pages: 726-749

    • DOI

      10.1017/jsl.2019.18

    • Related Report
      2018 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Finite Choice, Convex Choice and Sorting2019

    • Author(s)
      Takayuki Kihara, and Arno Pauly
    • Journal Title

      Lecture Notes in Computer Science

      Volume: 11436 Pages: 378-393

    • DOI

      10.1007/978-3-030-14812-6_23

    • ISBN
      9783030148119, 9783030148126
    • Related Report
      2018 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] The binary expansion and the intermediate value theorem in constructive reverse mathematics2018

    • Author(s)
      Josef Berger, Hajime Ishihara, Takayuki Kihara, and Takako Nemoto
    • Journal Title

      Archive for Mathematical Logic

      Volume: 58 Issue: 1-2 Pages: 203-217

    • DOI

      10.1007/s00153-018-0627-2

    • Related Report
      2018 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] The uniform Martin’s conjecture for many-one degrees2018

    • Author(s)
      Kihara Takayuki, Montalban Antonio
    • Journal Title

      Transactions of the American Mathematical Society

      Volume: 掲載決定済 Issue: 12 Pages: 9025-9044

    • DOI

      10.1090/tran/7519

    • Related Report
      2017 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Higher randomness and lim-sup forcing within and beyond hyperarithmetic2017

    • Author(s)
      Kihara Takayuki
    • Journal Title

      Lecture Notes Series, Institute for Mathematical Sciences, National University of Singapore:

      Volume: 33 Pages: 117-155

    • DOI

      10.1142/9789813223523_0006

    • Related Report
      2017 Annual Research Report
    • Peer Reviewed
  • [Presentation] The Brouwer invariance theorems in reverse mathematics2019

    • Author(s)
      Takayuki Kihara
    • Organizer
      The 9th International Conference on Computability Theory and Foundations of Mathematics
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] Weihrauch Counterparts of Reverse Mathematical Principles2018

    • Author(s)
      Takayuki Kihara
    • Organizer
      The 2018 North American Annual Meeting of the Association for Symbolic Logic
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] On the Structure of the Wadge degrees of BQO-valued Borel functions2018

    • Author(s)
      Takayuki Kihara
    • Organizer
      The Logic Colloquium 2018: the 2018 annual European Summer Meeting of the Association for Symbolic Logic
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] Weihrauch reducibility for some 3rd order principles2018

    • Author(s)
      Takayuki Kihara
    • Organizer
      Dagstuhl Seminar, Measuring the Complexity of Computational Content: From Combinatorial Problems to Analysis
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] Computability Theoretic Methods in Descriptive Set Theory2018

    • Author(s)
      Takayuki Kihara
    • Organizer
      Symposium on Advances in Mathematical Logic 2018
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Degrees of non-computability of points in general spaces2018

    • Author(s)
      Takayuki Kihara
    • Organizer
      Thirteenth International Conference on Computability, Complexity and Randomness
    • Related Report
      2018 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] Topologizing the degree theory2018

    • Author(s)
      Takayuki Kihara
    • Organizer
      Oberwolfach workshop on Computability Theory
    • Related Report
      2017 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] Ordinal ranks on the Baire and non-Baire class functions2018

    • Author(s)
      Takayuki Kihara
    • Organizer
      The second workshop on Mathematical Logic an Applications
    • Related Report
      2017 Annual Research Report
    • Int'l Joint Research
  • [Presentation] The ultimate analysis of some hierarchies under AD+2018

    • Author(s)
      Takayuki Kihara
    • Organizer
      手形L4研究集会
    • Related Report
      2017 Annual Research Report
    • Invited
  • [Presentation] De Groot duality in computability theory2017

    • Author(s)
      Takayuki Kihara
    • Organizer
      The 15th Asian Logic Conference
    • Related Report
      2017 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Martin-like phenomena in the classification of real-valued functions2017

    • Author(s)
      Takayuki Kihara
    • Organizer
      Fourteenth International Conference on Computability and Complexity in Analysis
    • Related Report
      2017 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] Wadge-like classifications of real valued functions2017

    • Author(s)
      Takayuki Kihara
    • Organizer
      Aspects of Computation: in celebration of the research work of Professor Rod Downey
    • Related Report
      2017 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] Borel isomorphisms at the second level2017

    • Author(s)
      Takayuki Kihara
    • Organizer
      The 2nd Pan Pacific International Conference on Topology and Applications
    • Related Report
      2017 Annual Research Report
    • Int'l Joint Research
  • [Presentation] 強無限次元カントール多様体による effective forcing について2017

    • Author(s)
      Takayuki Kihara
    • Organizer
      RIMS 共同研究「証明論と証明活動」
    • Related Report
      2017 Annual Research Report
  • [Remarks]

    • URL

      http://www.math.mi.i.nagoya-u.ac.jp/~kihara/index-j.html

    • Related Report
      2018 Annual Research Report
  • [Remarks] 名古屋ロジックセミナー

    • URL

      http://www.math.mi.i.nagoya-u.ac.jp/~kihara/logic-seminar.html

    • Related Report
      2017 Annual Research Report

URL: 

Published: 2017-08-25   Modified: 2022-05-23  

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