About

Tim Black
Pronouns: he/him

Research area
Combinatorics and Theoretical Computer science

University Teaching
Department of Computer Science, University of Chicago, 2017–2022
Assistant Instructional Professor (2019–2022)
Graduate Student Instructor (2017–2019)

Department of Mathematics, University of Chicago, 2012–2017
Graduate Student Instructor (2013–2017)
College Fellow (2012–2013)

Education, degrees
University of Chicago
Ph.D. in Mathematics and Computer Science, 2019
Advisor: Prof. László Babai

University of Chicago
M.S., Mathematics, 2013

California Insitute of Technology
B.S., Mathematics, 2011

Email
tim [my last name] 'at' gmail.com

Research

My research interest is in theoretical computer science (TCS) and discrete mathematics. TCS is in the overlap of mathematics and computer science; it deals with the rigorous analysis of algorithms and mathematical models of computation. Specifically, I have worked in the complexity theory of Boolean functions and in algorithmic coding theory. An overarching theme of my work has been the application of group theory to algorithms and complexity theory.

I am often drawn to problems with a discrete, symmetrical structure that is simple to describe but hard to analyze.

Publications

1. Timothy Black. Group-Theoretic Aspects of Complexity Theory and Coding Theory. PhD thesis, The University of Chicago, 2019.

2. László Babai, Timothy Black, and Angela Wuu. List-Decoding Homomorphism Codes with Arbitrary Codomains. In Approximation, Randomization, and Combinatorial Optimization. Algorithms and Techniques, APPROX/RANDOM 2018, pages 29:1-29:18. Schloss Dagstuhl–Leibniz-Zentrum fuer Informatik, 2018. Link to arXiv version.

3. Timothy Black. Monotone Properties of k-Uniform Hypergraphs are Weakly Evasive. ACM Trans. Comput. Theory, 11(3):14:1–14:14, April 2019. Previous, conference version: In Proceedings of the 2015 Conference on Innovations in Theoretical Computer Science (ITCS '15), pp 383-391. 2015. Best Student Paper Award. Use this link for free access to the conference version (but don't click on the "Tim's homepage" link on that page; it will take you to an old version of the site).

4. Timothy Black. Products of alternating groups are universally economically list-decodable. In preparation.

5. Timothy Black, Alan Guo, Madhu Sudan, and Angela Wuu. List-decoding group homomorphisms to nilpotent groups. In preparation.

Teaching

I taught at the University of Chicago from 2012 to 2022, first as a graduate student from 2012 to 2019, and then as an Assistant Instructional Professor from 2019 to 2022. I've taught in both the Math and Computer Science departments.

Computer Science instructor, 2017–2022

Linear Algebra with Applications - CAPP 30270 (graduate course), Winter 2020.

Mathematics for Computer Science and Data Analysis - CAPP 30271 (graduate course), Winter 2022, Winter 2021 (remote), Winter 2019.

Theory of Algorithms - CS 272, Spring 2021 (remote).

Graph Theory - CS 275, Winter 2022.

Computer Science with Applications 1 - CS 121, Autumn 2021 (two sections), Autumn 2020 (two sections, remote), Autumn 2019 (two sections), Autumn 2018, Autumn 2017.

Computer Science with Applications 2 - CS 122, Winter 2020.

Introduction to Computer Science I - CS 151, Spring 2022 (two sections), Spring 2021 (remote), Winter 2021 (remote), Spring 2020 (two sections, remote), Winter 2018.

Mathematics instructor, 2013–2017

Honors Calculus, Inquiry-Based Learning - Math 161, 162, 163, Autumn 2016–Spring 2017 (full year course) — coteaching with Sarah Ziesler.

Calculus - Math 151, 152, and 153, Autumn 2015–Winter 2016 (Math 152 and 153 only), Autumn 2013–Spring 2014 (full year course).

Elem Functions And Calculus - Math 131, 132, and 133, Autumn 2014–Spring 2015 (full year course).

Mathematics — other roles

Special Course Assistant for UChicago Math Study Abroad at the University of Chicago Center in Paris, Spring 2016.

College Fellow, Analysis in Rⁿ - Math 203, 204, and 205, 2012-2013 — teaching assistant for Alex Eskin, Hung Tran, and Inna Zakherevich.

Personal

Projects

Projective Set is a game played with a deck of 63 cards. Seven cards are placed on the table. Your goal is to find, among those seven cards, a set of those cards such that each color of dot appears on an even number of cards in your set. I designed the interface and wrote this web app in 2010. When you find a set, drag it toward the side of the screen.

Absurdliar is a word guessing game like Wordle or Lingo, with a twist. It combines the challenges of two other Wordle variants: Absurdle by qntm and Word Lie by Misha Lavrov. Inspired by these games, I created Absurdliar and wrote this web app in 2022.

Math blog: I've written blog posts on puzzles from FiveThirtyEight's The Riddler column. (Please note that the posts are hosted on an old site; avoid using the "Back to Tim's Homepage" link as it will take you to the old site. I will move the posts over to this site in the future.)

Shorter posts:

• Three reasons Riddler casino game has a beautiful value
• Don't get dizzy on the circular train
• Chaos tag is way slower than team tag
• To solve the Riddler without messy calculations, visit the Red Ball Casino
• Symmetry is hard - the plight of the paratroopers
• Volcanic islands? What do you expect?
• A nice day at the pond with my brain and my computer

Longer posts:

• Rock-paper-scissors-hop: Discrete hops are hard, so follow the continuous firefly
• Noble Knights can shake hands without having to move very much - and without repeats
• How many spy retreats? Information stealers meet Information Theory
• The probability that a triangle contains the origin - in any number of dimensions

Organizations I've worked with

UChicago Department of Computer Science.

UChicago Department of Mathematics.

Canada/USA Mathcamp is a wonderful summer program for students age 13-18 who are exceptional at math. Students come from around the world for the five-week program. I've been a mentor/faculty for seven summers, teaching interactive classes on topics including Infinitesimal Calculus with Hyperreal Numbers; Max-Flow Min-Cut; Error-Correcting Codes; Linear Programming; Fourier Analysis on the Boolean Cube; Decision Tree Complexity and Evasiveness; Machine Learning; Probabilistically Checkable Proofs of Proximity; Multiparty Communication Complexity; The Probabilistic Method; Sperner's Lemma; and Turing completeness and mechanical computers. I've been affiliated with Mathcamp from long before that; my first summer was as a camper in 2005.

Math Circles of Chicago provides students in grades 5 through 12 in all communities of Chicago access to actively participate in mathematics using innovative games and activities. From 2016 to 2019, I taught students from grades 7 to 12, and designed curricula for the Euler sessions (for advanced students) at the UChicago YSP Math Circle.