Graduate Logic Seminar: Difference between revisions

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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:''' Mondays 4p-5p (unless stated otherwise)
* '''When:''' Mondays 3:30-4:30 PM
* '''Where:''' on line (ask for code).
* '''Where:''' Van Vleck B139
* '''Organizers:''' [https://www.math.wisc.edu/~jgoh/ Jun Le Goh]
* '''Organizers:''' Karthik Ravishankar and [https://sites.google.com/wisc.edu/antonio Antonio Nakid Cordero]


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 one of the organizers.
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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


== Fall 2020 - Tentative schedule ==
== Fall 2022 ==


=== September 14 - Josiah Jacobsen-Grocott ===
=== September 12 - Organizational Meeting ===


Title: Degrees of points in topological spaces
We will meet to assign speakers to dates.


Abstract: An overview of some results from Takayuki Kihara, Keng Meng Ng, and Arno Pauly in their paper Enumeration Degrees and Non-Metrizable Topology. We will look at a range of topological spaces and the corresponding classes in the enumeration degrees as well as ways in which we can distinguish the type of classes using the separation axioms.
=== '''September 19 - Karthik Ravishankar''' ===
'''Title:''' Lowness for Isomorphism


=== September 28 - James Hanson ===
'''Abstract:''' A Turing degree is said to be low for isomorphism if it can only compute an isomorphism between computable structures only when a computable isomorphism already exists. In this talk, we show that the measure of the class of low for isomorphism sets in Cantor space is 0 and that no Martin Lof random is low for isomorphism.


Title: The Semilattice of Definable Sets in Continuous Logic
=== '''September 26 - Antonio Nakid Cordero''' ===
'''Title:''' When Models became Polish: an introduction to the Topological Vaught Conjecture


Abstract: After an analysis-free exposition of definable sets in continuous logic, we will present a fun, illustrated proof that any finite bounded lattice can be the poset of definable subsets of $S_1(T)$ for a continuous theory $T$.
'''Abstract:''' Vaught's Conjecture, originally asked by Vaught in 1961, is one of the most (in)famous open problems in mathematical logic. The conjecture is that a complete theory on a countable language must either have countably-many or continuum-many non-isomorphic models. In this talk, we will discuss some of the main ideas that surround this conjecture, with special emphasis on a topological generalization in terms of the continuous actions of Polish groups.


=== October 5 - Tejas Bhojraj from 3:30PM-4:00PM ===
=== '''October 3 - Yunting Zhang''' ===


Title: A Levin-Schnorr type result for Weak Solovay random states.
=== '''October 10 - Yuxiao Fu''' ===


Abstract: We look at the initial-segment complexity of Weak Solovay quantum random states using MK, a prefix-free version of quantum Kolmogorov complexity. The statement of our result is similar to the Levin-Schnorr theorem in classical algorithmic randomness.
=== '''October 17 - Alice Vidrine''' ===


=== November 9 - Karthik Ravishankar ===
=== '''October 24 - Hongyu Zhu''' ===


Title: Elementary submodels in infinite combinatorics
=== '''October 31 - Break for Halloween''' ===


Abstract: The usage of elementary submodels is a simple but powerful method to prove theorems, or to simplify proofs in infinite combinatorics. In the first part of the talk, we quickly cover the basic concepts involved for proving results using elementary submodels, and move on to provide two examples of application of the technique to prove two popular results from set theory: The Delta System lemma and the Fodors Pressing down lemma . We provide both the classical proof as well as a proof using elementary submodels to contrast the two approaches.
=== '''November 7 - John Spoerl''' ===


=== November 16 - Karthik Ravishankar ===
=== '''November 14 - Josiah Jacobsen-Grocott''' ===


Title: Elementary submodels in infinite combinatorics, part II
=== '''November 21 - Karthik Ravishankar''' ===


Abstract: In the second part of the talk, we give a proof Fodors Pressing down lemma, along with an overview of the slightly larger proof of the Nash Williams theorem which states that a graph is decomposable as a disjoint union of cycles if and only if it has no odd cut.
=== '''November 28 - Logan Heath''' ===


=== Tuesday, November 24 - Tonicha Crook (Swansea University) from 9:00AM-10:00AM ===
=== '''December 5 - Logan Heath''' ===


Title: The Weihrauch Degree of Finding Nash Equilibria in Multiplayer Games
=== '''December 12 - TBA''' ===


Abstract: Is there an algorithm that takes a game in normal form as input, and outputs a Nash equilibrium? If the payoffs are integers, the answer is yes, and a lot of work has been done in its computational complexity. If the payoffs are permitted to be real numbers, the answer is no, for continuity reasons. It is worthwhile to investigate the precise degree of non-computability (the Weihrauch degree), since knowing the degree entails what other approaches are available (eg, is there a randomized algorithm with positive success change?). The two player case has already been fully classified, but the multiplayer case remains open and is addressed here. As well as some insight into finding the roots of polynomials, which is essential in our research. An in-depth introduction to Weihrauch Reducibility will be included in the presentation, along with a small introduction to Game Theory.
== Previous Years ==
 
=== November 30 - Yvette Ren ===
 
Title: Enumeration Degrees and Topology
 
Abstract: I will introduce three classes of enumeration degrees: co-dcea degrees, telegraph-cototal degrees and cylinder-cototal degrees and discuss the relations between each other. Selected results from Kihara, Pauly, and Ng’s paper ''Enumeration Degrees and Non-Metrizable Topology'' and their alternative proofs will be presented.
 
==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]].

Revision as of 07:20, 26 September 2022

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 B139
  • Organizers: Karthik Ravishankar and Antonio Nakid Cordero

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 2022

September 12 - Organizational Meeting

We will meet to assign speakers to dates.

September 19 - Karthik Ravishankar

Title: Lowness for Isomorphism

Abstract: A Turing degree is said to be low for isomorphism if it can only compute an isomorphism between computable structures only when a computable isomorphism already exists. In this talk, we show that the measure of the class of low for isomorphism sets in Cantor space is 0 and that no Martin Lof random is low for isomorphism.

September 26 - Antonio Nakid Cordero

Title: When Models became Polish: an introduction to the Topological Vaught Conjecture

Abstract: Vaught's Conjecture, originally asked by Vaught in 1961, is one of the most (in)famous open problems in mathematical logic. The conjecture is that a complete theory on a countable language must either have countably-many or continuum-many non-isomorphic models. In this talk, we will discuss some of the main ideas that surround this conjecture, with special emphasis on a topological generalization in terms of the continuous actions of Polish groups.

October 3 - Yunting Zhang

October 10 - Yuxiao Fu

October 17 - Alice Vidrine

October 24 - Hongyu Zhu

October 31 - Break for Halloween

November 7 - John Spoerl

November 14 - Josiah Jacobsen-Grocott

November 21 - Karthik Ravishankar

November 28 - Logan Heath

December 5 - Logan Heath

December 12 - TBA

Previous Years

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