Difference between revisions of "Graduate Logic Seminar"

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(October 26 - Alice Vidrine)
 
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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:''' Tuesdays 4-5 PM
* '''Where:''' on line (ask for code).
+
* '''Where:''' Van Vleck 901
 
* '''Organizers:''' [https://www.math.wisc.edu/~jgoh/ Jun Le Goh]
 
* '''Organizers:''' [https://www.math.wisc.edu/~jgoh/ Jun Le Goh]
  
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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:  join-grad-logic-sem@lists.wisc.edu
  
== Spring 2021 - Tentative schedule ==
+
== Fall 2021 tentative schedule ==
  
=== February 16 3:30PM - Short talk by Sarah Reitzes (University of Chicago) ===
+
To see what's happening in the Logic qual preparation sessions click [[Logic Qual Prep|here]].
  
Title: Reduction games over $\textup{RCA}_0$
+
=== September 14 - organizational meeting ===
  
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 $\textup{RCA}_0 \vdash$ 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 $\textup{RCA}_0$. In this talk, I will explore these notions of reduction among various principles, including bounding and induction principles.
+
We met to discuss the schedule.
  
==Previous Years==
+
=== September 28 - Ouyang Xiating ===
 +
 
 +
Title: First-order logic, database and consistent query answering
 +
 
 +
Abstract: Databases are a crucial component of many (if not all) modern
 +
applications. In reality, the data stored are often dirty and contain
 +
duplicated/missing entries, and it is a natural practice to clean the data
 +
first before executing the query. However, the same query might return
 +
different answers on different cleaned versions of the dataset. It is then
 +
helpful to compute the consistent answers: the query answers that will always
 +
be returned, regardless of how the dirty data is cleaned. In this talk, we
 +
first introduce the connection between first-order logic and query languages
 +
on databases, and then discuss the problem of Consistent Query Answering
 +
(CQA): How to compute consistent answers on dirty data? Finally, we show
 +
when the CQA problem can be solved using first-order logic for path queries.
 +
 
 +
=== October 12 - Karthik Ravishankar ===
 +
 
 +
Title: Notions of randomness for subsets of the Natural Numbers
 +
 
 +
Abstract: There are a number of notions of randomness of sets of natural numbers. These notions have been defined based on what a 'random object' should behave like such as being 'incompressible' or being 'hard to predict' etc. There is often a interplay between computability and randomness aspects of subsets of natural numbers. In this talk we motivate and present a few different notions of randomness and compare their relative strength.
 +
 
 +
=== October 26 - Alice Vidrine ===
 +
 
 +
Title: Categorical logic for realizability, part III: Actual realizability
 +
 
 +
Abstract: Realizability is an approach to semantics for non-classical logic that interprets propositions by sets of abstract computational data. In the present talk we describe the notion of a Schonfinkel algebra (also called a partial combinatory algebra), which gives us a very general notion of computation. We then describe the construction of a topos whose notions of morphism and subobject must respect the computational structure, and describe the unusual features of these toposes, closing with some discussion of Lawvere-Tierney topologies on such toposes.
 +
 
 +
(The abstracts for parts I and II, which were given in spring 2021, can be found [https://hilbert.math.wisc.edu/wiki/index.php/Graduate_Logic_Seminar,_previous_semesters#March_30_4PM_-_Alice_Vidrine here].)
 +
 
 +
=== November 9 - Antonio Nákid Cordero ===
 +
 
 +
=== November 23 - Antonio Nákid Cordero? ===
 +
 
 +
=== December 7 - John Spoerl ===
 +
 
 +
== 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 20:45, 21 October 2021

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: Tuesdays 4-5 PM
  • Where: Van Vleck 901
  • Organizers: Jun Le Goh

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

Sign up for the graduate logic seminar mailing list: join-grad-logic-sem@lists.wisc.edu

Fall 2021 tentative schedule

To see what's happening in the Logic qual preparation sessions click here.

September 14 - organizational meeting

We met to discuss the schedule.

September 28 - Ouyang Xiating

Title: First-order logic, database and consistent query answering

Abstract: Databases are a crucial component of many (if not all) modern applications. In reality, the data stored are often dirty and contain duplicated/missing entries, and it is a natural practice to clean the data first before executing the query. However, the same query might return different answers on different cleaned versions of the dataset. It is then helpful to compute the consistent answers: the query answers that will always be returned, regardless of how the dirty data is cleaned. In this talk, we first introduce the connection between first-order logic and query languages on databases, and then discuss the problem of Consistent Query Answering (CQA): How to compute consistent answers on dirty data? Finally, we show when the CQA problem can be solved using first-order logic for path queries.

October 12 - Karthik Ravishankar

Title: Notions of randomness for subsets of the Natural Numbers

Abstract: There are a number of notions of randomness of sets of natural numbers. These notions have been defined based on what a 'random object' should behave like such as being 'incompressible' or being 'hard to predict' etc. There is often a interplay between computability and randomness aspects of subsets of natural numbers. In this talk we motivate and present a few different notions of randomness and compare their relative strength.

October 26 - Alice Vidrine

Title: Categorical logic for realizability, part III: Actual realizability

Abstract: Realizability is an approach to semantics for non-classical logic that interprets propositions by sets of abstract computational data. In the present talk we describe the notion of a Schonfinkel algebra (also called a partial combinatory algebra), which gives us a very general notion of computation. We then describe the construction of a topos whose notions of morphism and subobject must respect the computational structure, and describe the unusual features of these toposes, closing with some discussion of Lawvere-Tierney topologies on such toposes.

(The abstracts for parts I and II, which were given in spring 2021, can be found here.)

November 9 - Antonio Nákid Cordero

November 23 - Antonio Nákid Cordero?

December 7 - John Spoerl

Previous Years

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