Research: I have been reseearching computational imaging since 2023 with Prof. Kyros Kutulakos and Prof. David Lindell. I have also participated in several abstract mathematics research on finite- and infinite-dimensional smooth groups and their applications in mathematical physics. Please see further details below.
Teaching: I have been a Teaching Assistant in the Department of Mathematics at the University of Toronto for 3 semesters. I have TA-ed first-year linear algebra courses, including MAT240H1 and MAT247H1. I have some notes and talks, which are included below.
Work: I have completed a full-year internship at Bell Canada, during which I developed internal AI-based software tools using langchain and Ollama.
Research
Broadly speaking, my current research interest is in designing imaging systems that surpass conventional technologies and reveal previously unseen phenomena.
I envision future imaging systems to be biologically, mathematically, and computationally inspired, end-to-end optimized, requiring minimal energy, gaining maximal sensory information, flexible to various tasks with on-sensor and off-sensor learning, robust to challenging scenarios, and suitable for specific tasks.
During my current research in TCIG, I am working with single-photon avalanche diodes (SPADs) — sensors capable of timestamping photon arrivals with extreme precision and no read noise. This sensor unlocks exciting capabilities for both passive and active imaging tasks and presents applications in other domains such as biomedical science, neuroscience, astronomy, and chemistry.
In my mathematics research, I am developing mathematical structures for smooth groupoids and connecting these novel structures to dynamical systems in mathematical physics. The dynamical systems framework is highly relevant to
imaging systems that manipulate light, analyze dynamics in light-matter interaction, model wave propagation, or optimize optical components over time.
Computational Imaging
Opportunistic Single-Photon Time of Flight
Sotiris Nousias*, Mian Wei* (joint first author), Howard Xiao, Maxx Wu, Shahmeer Athar, Kevin J Wang, Anagh Malik, David A. Barmherzig, David B. Lindell, Kyros Kutulakos.
November, 2024. Submitted and under review.
Can we use ambient light in our environment, such as those from asynchronous lidar systems, for passive 3D vision?
Code pipeline taking in an increasing stream of photon timestamps captured by unsynchronized single-photon avalanche diode (SPAD) and completes steps of ultra-wideband probing, frequency thresholding and 1-dimensional flux reconstruction for multiple asynchronous periodic sources (unsynchronized picosecond lasers, projectors, etc.)
Mathematics
Broken Virasoro Groupoid
Howard Xiao, Anton Izosimov, Boris Khesin.
In preparation, 2025
Understand the structure of central extensions of the Virasoro groupoid and algebroid, classify their cocycles and co-adjoint actions, and study the corresponding equations in mathematical physics.
I completed a four-month independent reading course with Prof. Eckhard Meinrenken at the University of Toronto. I studied the actions of Lie groups and
Lie algebras, compact Lie groups, maximal tori, and the classification of finite-dimensional compact Lie groups using root systems.
Talk: I have given a talk at the Canadian Undergraduate Mathematics Conference (CUMC) 2023 on gaining intuition behinds analysis using everyday language analogies. The video link is here. See also my notes on this topic. (For U of T students: the material roughly coincides with MAT157Y1 but is presented using analogies from natural languages. )
Other Notes: Please see here for another set of notes titled "Abstract Algebra Toolbox". I started typing this set of notes under the impression that manipulation of groups, rings, and fields is really applying certain set of tools in a toolkit. I think presenting in this way makes it more organized. This set of notes follows Abstract Algebra by Dummit and Foote.