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The Graduate Logic Seminar is an informal space where graduate students and professors present topics related to logic which are not necessarily original or completed work. This is a space focused principally on practicing presentation skills or learning materials that are not usually presented in a class.
The Graduate Logic Seminar is an informal space where graduate students and professors present topics related to logic which are not necessarily original or completed work. This is a space focused principally on practicing presentation skills or learning materials that are not usually presented in a class.


* '''When:''' TBA
* '''When:''' Mondays 3:30-4:30 PM
* '''Where:''' on line (ask for code).
* '''Where:''' Van Vleck B235
* '''Organizers:''' [https://www.math.wisc.edu/~jgoh/ Jun Le Goh]
* '''Organizer:''' Mariya Soskova


The talk schedule is arranged at the beginning of each semester. If you would like to participate, please contact one of the organizers.
The talk schedule is arranged at the beginning of each semester. If you would like to participate, please contact the organizers.


Sign up for the graduate logic seminar mailing list:  join-grad-logic-sem@lists.wisc.edu
<!--Sign up for the graduate logic seminar mailing list:  [mailto:join-grad-logic-sem@lists.wisc.edu join-grad-logic-sem@lists.wisc.edu]-->


== Spring 2021 - Tentative schedule ==
== Spring 2025 ==


=== February 16 3:30PM - Short talk by Sarah Reitzes (University of Chicago) ===
The seminar will be run as a 1-credit seminar Math 975. In Spring 2025, we will finish last semester's topic on Higher Computability Theory.Once we are done students will present a logic topic of their choice (it could be original work, but does not have to be).  If you are not enrolled but would like to audit it, please contact [mailto:soskova@wisc.edu Mariya Soskova].


Title: Reduction games over $\mathrm{RCA}_0$
Presentation Schedule: [https://docs.google.com/spreadsheets/d/1uRSaI1edJ5sepz57NV07ohIfBSKL9FgkvJvMAewk1ms/edit?usp=sharing Sign up here.]


Abstract: In this talk, I will discuss joint work with Damir D. Dzhafarov and Denis R. Hirschfeldt. Our work centers on the characterization of problems P and Q such that P $\leq_{\omega}$ Q, as well as problems P and Q such that $\mathrm{RCA}_0 \vdash$ Q $\to$ P, in terms of winning strategies in certain games. These characterizations were originally introduced by Hirschfeldt and Jockusch. I will discuss extensions and generalizations of these characterizations, including a certain notion of compactness that allows us, for strategies satisfying particular conditions, to bound the number of moves it takes to win. This bound is independent of the instance of the problem P being considered. This allows us to develop the idea of Weihrauch and generalized Weihrauch reduction over some base theory. Here, we will focus on the base theory $\mathrm{RCA}_0$. In this talk, I will explore these notions of reduction among various principles, including bounding and induction principles.
Notes on Higher Computability Theory: [https://uwmadison.box.com/s/j3xftdj1i70d4lblxhzswhg9e25ajcpq Download the notes here.] You will need your UW-login. Please, do not distribute these notes without permission from the author.  


=== March 23 4:15PM - Steffen Lempp ===
<!--Zoom link for remote attendance: https://uwmadison.zoom.us/j/96168027763?pwd=bGdvL3lpOGl6QndQcG5RTFUzY3JXQT09 (Meeting ID: 961 6802 7763, Password: 975f23)-->


Title: Degree structures and their finite substructures
=== '''January 27 - Organizational Meeting and Sapir Ben-Shahar''' ===


Abstract: Many problems in mathematics can be viewed as being coded by sets of natural numbers (as indices).
Mariya Soskova will call for volunteers to sign up for presentations.  
One can then define the relative computability of sets of natural numbers in various ways, each leading to a precise notion of “degree” of a problem (or set).
In each case, these degrees form partial orders, which can be studied as algebraic structures.
The study of their finite substructures leads to a better understanding of the partial order as a whole.


=== March 30 4PM - Alice Vidrine ===
Sapir Ben-Shahar will wrap up Section 5.1


Title: Categorical logic for realizability, part I: Categories and the Yoneda Lemma
=== '''February 3 -  Taeyoung Em''' ===


Abstract: An interesting strand of modern research on realizability--a semantics for non-classical logic based on a notion of computation--uses the language of toposes and Grothendieck fibrations to study mathematical universes whose internal notion of truth is similarly structured by computation. The purpose of this talk is to establish the basic notions of category theory required to understand the tools of categorical logic developed in the sequel, with the end goal of understanding the realizability toposes developed by Hyland, Johnstone, and Pitts. The talk will cover the definitions of category, functor, natural transformation, adjunctions, and limits/colimits, with a heavy emphasis on the ubiquitous notion of representability.
Taeyoung Em will present Section 5.3.  


[https://hilbert.math.wisc.edu/wiki/images/Cat-slides-1.pdf Link to slides]
=== '''February 10 - Hongyu Zhu''' ===


=== April 27 4PM - Alice Vidrine ===
Hongyu Zhu will present Section 5.3


Title: Categorical logic for realizability, part II
=== '''February 17 -  Karthik Ravishankar''' ===


Abstract: Realizability is an approach to semantics for non-classical logic that interprets propositions by sets of abstract computational data. One modern approach to realizability makes heavy use of the notion of a topos, a type of category that behaves like a universe of non-standard sets. In preparation for introducing realizability toposes, the present talk will be a brisk introduction to the notion of a topos, with an emphasis on their logical aspects. In particular, we will look at the notion of a subobject classifier and the internal logic to which it gives rise.
'''Title:''' Strong minimal covers and the cupping property


==Previous Years==
'''Abstract:''' A longstanding question in degree theory has been whether every minimal Turing degree has a strong minimal cover. Meanwhile a strong example of degrees without SMC's are those which have the cupping property. It is known that PA degrees have the cupping property, as do degrees with a certain amount of escaping power. On the other hand, it is known that being weak in the sense of being non DNC and Hyperimmune-free lets you have a SMC. Degrees with the cupping property are closed upwards while it is not known if degrees with SMC are closed downwards.  It is also not known if every degree either has the cupping property or a SMC. In this talk we will review several of these results and present techniques used to build SMCs.
 
=== '''February 24 -  Hongyu Zhu''' ===
 
'''Title:''' tba
 
'''Abstract:''' tba
 
=== '''March 3 -  Uri Andrews''' ===
 
'''Title:''' tba
 
'''Abstract:''' tba
 
=== '''Macrh 10 -  Logan Heath''' ===
 
'''Title:''' tba
 
'''Abstract:''' tba
 
 
=== '''Macrh 17 -  Yiqing Wang''' ===
 
'''Title:''' tba
 
'''Abstract:''' tba
 
=== '''Macrh 31 -  Chiara Travesset''' ===
 
'''Title:''' tba
 
'''Abstract:''' tba
 
 
 
== Fall 2024 ==
 
The seminar will be run as a 1-credit seminar Math 975 . In Fall 2024, the topic will be Higher Computability Theory. We will follow notes by Noam Greenberg. If you are not enrolled but would like to audit it, please contact [mailto:soskova@wisc.edu Mariya Soskova].
 
Presentation Schedule: [https://docs.google.com/spreadsheets/d/1ect-dgHdoHOgq4-5BGFiDh6pPThLfDg69Yg__-b_5RY/edit?usp=sharing Sign up here.]
 
Notes: [https://uwmadison.box.com/s/j3xftdj1i70d4lblxhzswhg9e25ajcpq Download the notes here.] You will need your UW-login. Please, do not distribute these notes without permission from the author.
 
<!--Zoom link for remote attendance: https://uwmadison.zoom.us/j/96168027763?pwd=bGdvL3lpOGl6QndQcG5RTFUzY3JXQT09 (Meeting ID: 961 6802 7763, Password: 975f23)-->
 
=== '''September 9 - Organizational Meeting''' ===
 
Mariya Soskova will start with the first sections from the notes.
 
We will then assign speakers to dates and topics.
 
=== '''September 16 -  Sections 1.2-1.4''' ===
 
Kanav Madhura will continue with Sections 1.2-1.4.
 
=== '''September 23 -  Sections 1.3-1.4 and 2.1-2.2''' ===
 
Kanav Madhura will continue with Sections 1.3-1.4. Lucas Duckworth will be ready with Sections 2.1 and 2.2 should there be time.
 
=== '''September 30 -  Sections 2.2 and 2.3-2.5''' ===
 
Lucas Duckworth will finish Section 2.2. Karthik Ravishankar will begin 2.3, 2.4, and 2.5.
=== '''October 7th -  Sections 2.4 and 2.5''' ===
 
Karthik Ravishankar will  finish, 2.4, and 2.5.  Liang Yu will give a talk at 4:00pm.
 
=== '''October 14th -  Sections 2.6 and 2.7''' ===
 
Bjarki Gunnarsson  will present Sections 2.6 and 2.7
 
=== '''October 21th -  Section 3.1''' ===
 
Karthik Ravishankar will present Section 3.1 
 
=== '''October 28th -  Sections 3.2 and 3.3''' ===
 
Karthik Ravishankar will finish Sections 3.2  and John Spoerl will begin Section 3.3
 
=== '''November 4th -  Sections 3.3 and 3.4''' ===
 
John Spoerl will finish Sections 3.3 and 3.4
 
=== '''November 11th -  Section 4.1''' ===
 
Antonion Nakid-Cordero will present Section 4.1
 
=== '''November 19th -  Sections 4.1 and 4.2''' ===
 
Start 4:00PM in VV901! Antonion Nakid-Cordero will continue with Section 4.1, Ang Li will begin Section 4.2.
 
 
=== '''November 25th -  Sections 4.2 and 4.3''' ===
 
Back to the usual time and place. Ang Li will begin Section 4.2.
 
=== '''December 2nd -  Section 4.3''' ===
 
Ang Li will present Section 4.3.
 
=== '''December 9nd -  Section 5.1''' ===
 
Last seminar for this semester. Sapir Ben-Shahar will begin Section 5.1
 
<!-- Template
 
=== '''September 18 - xxx''' ===
'''Title:''' TBA ([https://wiki.math.wisc.edu/images/***.pdf Slides])
 
'''Abstract:''' TBA
 
-->
 
== Previous Years ==


The schedule of talks from past semesters can be found [[Graduate Logic Seminar, previous semesters|here]].
The schedule of talks from past semesters can be found [[Graduate Logic Seminar, previous semesters|here]].

Latest revision as of 13:19, 11 February 2025

The Graduate Logic Seminar is an informal space where graduate students and professors present topics related to logic which are not necessarily original or completed work. This is a space focused principally on practicing presentation skills or learning materials that are not usually presented in a class.

  • When: Mondays 3:30-4:30 PM
  • Where: Van Vleck B235
  • Organizer: Mariya Soskova

The talk schedule is arranged at the beginning of each semester. If you would like to participate, please contact the organizers.


Spring 2025

The seminar will be run as a 1-credit seminar Math 975. In Spring 2025, we will finish last semester's topic on Higher Computability Theory.Once we are done students will present a logic topic of their choice (it could be original work, but does not have to be). If you are not enrolled but would like to audit it, please contact Mariya Soskova.

Presentation Schedule: Sign up here.

Notes on Higher Computability Theory: Download the notes here. You will need your UW-login. Please, do not distribute these notes without permission from the author.


January 27 - Organizational Meeting and Sapir Ben-Shahar

Mariya Soskova will call for volunteers to sign up for presentations.

Sapir Ben-Shahar will wrap up Section 5.1

February 3 - Taeyoung Em

Taeyoung Em will present Section 5.3.

February 10 - Hongyu Zhu

Hongyu Zhu will present Section 5.3

February 17 - Karthik Ravishankar

Title: Strong minimal covers and the cupping property

Abstract: A longstanding question in degree theory has been whether every minimal Turing degree has a strong minimal cover. Meanwhile a strong example of degrees without SMC's are those which have the cupping property. It is known that PA degrees have the cupping property, as do degrees with a certain amount of escaping power. On the other hand, it is known that being weak in the sense of being non DNC and Hyperimmune-free lets you have a SMC. Degrees with the cupping property are closed upwards while it is not known if degrees with SMC are closed downwards. It is also not known if every degree either has the cupping property or a SMC. In this talk we will review several of these results and present techniques used to build SMCs.

February 24 - Hongyu Zhu

Title: tba

Abstract: tba

March 3 - Uri Andrews

Title: tba

Abstract: tba

Macrh 10 - Logan Heath

Title: tba

Abstract: tba


Macrh 17 - Yiqing Wang

Title: tba

Abstract: tba

Macrh 31 - Chiara Travesset

Title: tba

Abstract: tba


Fall 2024

The seminar will be run as a 1-credit seminar Math 975 . In Fall 2024, the topic will be Higher Computability Theory. We will follow notes by Noam Greenberg. If you are not enrolled but would like to audit it, please contact Mariya Soskova.

Presentation Schedule: Sign up here.

Notes: Download the notes here. You will need your UW-login. Please, do not distribute these notes without permission from the author.


September 9 - Organizational Meeting

Mariya Soskova will start with the first sections from the notes.

We will then assign speakers to dates and topics.

September 16 - Sections 1.2-1.4

Kanav Madhura will continue with Sections 1.2-1.4.

September 23 - Sections 1.3-1.4 and 2.1-2.2

Kanav Madhura will continue with Sections 1.3-1.4. Lucas Duckworth will be ready with Sections 2.1 and 2.2 should there be time.

September 30 - Sections 2.2 and 2.3-2.5

Lucas Duckworth will finish Section 2.2. Karthik Ravishankar will begin 2.3, 2.4, and 2.5.

October 7th - Sections 2.4 and 2.5

Karthik Ravishankar will finish, 2.4, and 2.5. Liang Yu will give a talk at 4:00pm.

October 14th - Sections 2.6 and 2.7

Bjarki Gunnarsson will present Sections 2.6 and 2.7

October 21th - Section 3.1

Karthik Ravishankar will present Section 3.1

October 28th - Sections 3.2 and 3.3

Karthik Ravishankar will finish Sections 3.2 and John Spoerl will begin Section 3.3

November 4th - Sections 3.3 and 3.4

John Spoerl will finish Sections 3.3 and 3.4

November 11th - Section 4.1

Antonion Nakid-Cordero will present Section 4.1

November 19th - Sections 4.1 and 4.2

Start 4:00PM in VV901! Antonion Nakid-Cordero will continue with Section 4.1, Ang Li will begin Section 4.2.


November 25th - Sections 4.2 and 4.3

Back to the usual time and place. Ang Li will begin Section 4.2.

December 2nd - Section 4.3

Ang Li will present Section 4.3.

December 9nd - Section 5.1

Last seminar for this semester. Sapir Ben-Shahar will begin Section 5.1


Previous Years

The schedule of talks from past semesters can be found here.