Welcome to my site! I am a master's student in mathematics under the supervision of Louigi Addario-Berry and Anush Tserunyan at McGill University. I also completed my undergraduate degree in mathematics at McGill. Broadly, I'm interested in stochastic processes, ergodic theory, measured group theory, and probability. I also have a pet interest in [[Notes|category theory]]. I mainly use this site to share my math notes. I also welcome any emails about accessibility concerns. :) # More about me **Research Interests:** My research interests centre on the intersection of measurable group theory and ergodic theory with discrete probability and combinatorics. See e.g. Lyons' *Probability on Trees and Networks* for an idea of the kind of math I am interested in. Basically, I like the conversation between geometric/algebraic properties of countable graphs and the stochastic behaviour of various models defined on said graphs. **Publications:** "Oscillating and nonsummable Radon-Nikodym cocycles along the forward geodesic of measure-class-preserving transformations," with Sasha Bell and Owen Rodgers. Submitted to *Groups, Geometry, and Dynamics.* Preprint on *ArXiv* [here](https://arxiv.org/abs/2407.16967). *Abstract*: We consider the least-deletion map on the Cantor space, namely the map that changes the first 1 in a binary sequence to 0, and construct product measures on $2^\mathbb{N}$ so that the corresponding Radon-Nikodym cocycles oscillate or converge to zero nonsummably along the forward geodesic of the map. These examples answer two questions of Tserunyan and Tucker-Drob. We analyze the oscillating example in terms of random walks on $\mathbb{Z}$, using the Chung-Fuchs theorem. **Research experience:** In summer 2023, I did research in probability at McGill with [Louigi Addario-Berry](http://problab.ca/louigi/). I was funded by [SURA](https://www.mcgill.ca/science/research/undergraduate-research/sura). My first project consisted of writing a self-contained expository paper which fills in the details for a categorical approach to probability suggested by Gromov. My second project involved computing the variance of the number of local optima in the Sherrington-Kirkpatrick model. Both of these projects were moderately unsuccessful. I also taught category theory to interested colleagues in the lab each week. (My category theory lecture notes can be accessed in the notes section.) During the summer, I proved some novel useful properties about a special quasi-probability-measure-preserving transformation, working with Sasha Bell and Owen Rodgers, which was presented at McGill's [Descriptive Dynamics and Combinatorics seminar](https://www.math.mcgill.ca/atserunyan/DDC-Seminar/) in October 2023. (This work culminated in the preprint above.) In early 2022, I studied descriptive set theory and Polish spaces in McGill's Directed Reading Program with Ran Tao. In the summer of 2022, I completed a reading course in category theory with Professor [Prakash Panangaden](https://cs.mcgill.ca/~prakash/). In fall of 2022, I did an honours independent study with Professor Panangaden on Stone-type dualities. **Service work:** I was an organizer and photographer for SUMM 2024 (Seminars in Undergraduate Mathematics in Montreal). See [here](https://www.flickr.com/photos/199862491@N06/) for some pictures. I also helped organize McGill's 2023 summer [undergraduate research seminar](https://docs.google.com/spreadsheets/d/1CPBZnN05_sns4YwlCe9hhX-8Iwyipnv3b7w4QelLcKU/edit#gid=0) with Carl Kristof-Tessier. I run the Twitter account for a nonprofit called the [The Prison Mathematics Project](https://www.prisonmathproject.org/) which connects incarcerated individuals with math mentors. We recently fundraised over $2500 thanks to word of mouth and social media fundraising. I raised the Twitter follower count from 200 to over 1500. I also volunteer myself as a math mentor at the Prison Mathematics Project. I am teaching calculus over email to my amazing mentee Kevin. **Employment:** I worked for [Alloprof](https://www.alloprof.qc.ca/) for several years, where I translated and adapted French-language math and science pages to English. Though I no longer work there, it was a lovely company to work for and a great way to give back to people in the mathematical community of all ages. :) **GPA:** My undergrad GPA is 3.97 out of 4.0. **Awards**: My master's is funded by a NSERC Canada Graduate Scholarship-Master's (CGS-M), worth $23,834 and partial concurrent funding from Fonds de Recherche du Quebec (FRQNT), (total award is worth $40 000 but I only receive part of it). During the summer of 2023, I was awarded a $9000 Science Undergraduate Research Award (SURA). I received the J.W. McConnell scholarship from McGill for 2 years and the David Tat-Chi Lin scholarship for 1 year, for a total of $9000. **Seminar talks:** **Oct 2024**, McMaster University, BioDataLunch. *Abstract*: How do we find the origin of a rumour or patient 0 in a pandemic? This can be thought of as finding the root of a graph generated in a certain infectious way. We give new root reconstruction algorithms on two graph models (Bienaymé trees and the configuration model). This is joint work with Louigi Addario-Berry, Sasha Bell, and Théodore Conrad-Frenkiel. **Feb 2024,** McGill University, Descriptive Dynamics and Combinatorics Seminar. *Abstract:* Let $(X, \mu)$ be a standard probability space. We say a (not necessarily proper) colouring of a graph $G \subseteq X^2$ is $\kappa$-domatic, for $\kappa$ a cardinal, if each vertex $x \in G$ sees exactly $\kappa$ many different colours among its neighbours. We sketch a result of Edward Hou, 2022, which says any $\mu$-preserving $\omega$-regular Borel graph $G \subseteq X^2$ admits a $\mu$-measurable $\omega$-domatic colouring. This talk was given jointly with Owen Rodgers. Joint results of mine have also been presented at the **August 2024** Frontiers of Statistical Mechanics and Theoretical Computer Science (by Louigi Addario-Berry) and at the McGill Descriptive Dynamics and Combinatorics Seminar in **October 2023** (by Sasha Bell and Owen Rodgers). # Other places you can find me I write in a more casual setting about math on my [Twitter](https://twitter.com/taz_chu). Feel free to reach out and connect by emailing me at tazlchu[at]gmail[dot]com. For more on my work history, check out my [LinkedIn](https://www.linkedin.com/in/tasmin-chu-5769aa1b4/). # Equity in math I strongly believe that anyone who wants to do math belongs in math. Too often, we place an emphasis on "innate talent" or "genius" in mathematics. This disproportionately leads to minorities and women [disqualifying themselves](https://www.science.org/content/article/belief-some-fields-require-brilliance-may-keep-women-out) from participating in mathematics in the first place. My view could concisely be summarized as: More women should probably be in math. More minorities should probably be in math. Changing the status quo is worthy of our interest and attention.