Home /  DDC - Computability Theory: Effective ringed spaces and Turing degrees of isomorphism types

Seminar

DDC - Computability Theory: Effective ringed spaces and Turing degrees of isomorphism types September 18, 2020 (09:00 AM PDT - 10:00 AM PDT)
Parent Program:
Location: SLMath: Online/Virtual
Speaker(s) Wesley Calvert (Southern Illinois University)
Description

Hilbert’s Tenth Problem was the only decision problem among his twenty-three problems. Precise mathematical theory of (in)computability and its interaction with number theory led to the negative solution of the problem. The seminar will focus on modern topics on computability-theoretic phenomena in number-theoretic and other algebraic and model-theoretic structures.

To participate in this seminar, please register here: https://www.msri.org/seminars/25206

 

Keywords and Mathematics Subject Classification (MSC)
Primary Mathematics Subject Classification No Primary AMS MSC
Secondary Mathematics Subject Classification No Secondary AMS MSC
Video

Effective Ringed Spaces And Turing Degrees Of Isomorphism Types

Abstract/Media

To participate in this seminar, please register here: https://www.msri.org/seminars/25206

 

The Turing degree spectrum of a countable structure A is the set of all Turing degrees of isomorphic copies of A.  The Turing degree of the isomorphism type of A is the least degree in this spectrum, if there is a least degree.  Frequently one can prove that, for a given class K of structures (e.g., the class of fields), for any Turing degree d there is an element of K whose isomorphism type has degree d.  Frequently this result is established by finding that K has certain combinatorial properties.  Here we show that this universality property holds for various classes of ringed spaces: unions of subvarieties of a fixed variety, unions of arbitrary ringed spaces, and schemes.

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Effective Ringed Spaces And Turing Degrees Of Isomorphism Types

H.264 Video 25183_28681_8507_Effective_Ringed_Spaces_and_Turing_Degrees_of_Isomorphism_Types.mp4