Welcome!

In this website I will be writing about things I find interesting. I hope you stick around!

About me

My name is Themis and I am a PhD student at Boston University. I am advised by Krzysztof Onak. In the past, I was also fortunate to work with Alina Ene at BU and Amit Chakrabarti as an undergrad at Dartmouth College. Before starting grad school, I spent two years as a software engineer at Microsoft working on virtualization and the Windows Kernel, with the Base Kernel Team.

I study Theoretical Computer Science (TCS) and its applications on Machine Learning and Deep Learning. I have recently been excited about the following topics:

• Adversarially Robust Streaming Algorithms
• Differentially Private Mechanisms
• Efficient Algorithms for Approximating Self-Attention in Transformer Models
• Spectral Graph Theory and Random Processes
• Submodular Function Maximization
• Fine-Grained Average-Case Complexity Theory

I often blog about things I find interesting.

Contact

• Email: tharis at bu dot edu.
• Google Scholar!
• LinkedIn
• DBLP

Publications

2022

1. Counting Simplices in Hypergraph Streams, Amit Chakrabarti, Themistoklis Haris (ESA 2022)
   • Main idea: A hypergraph simplex generalizes a triangle. It is a collection of $k$ vertices for which all $k$ possible $(k-1)$-subsets are present hyperedges. We tackle the problem of counting these structures in a uniform hypergraph stream in low-memory regimes. We also provide lower bounds for this problem using communication complexity techniques.

2020

1. [Teaching American Sign Language In Mixed Reality], Qijia Shao, Amy Sniffen, Julien Blanchet, Megan E Hillis, Xinyu Shi, Themistoklis Haris, Jason Liu, Jason Lamberton, Melissa Malzkuhn, Lorna C Quandt, James Mahoney, David JM Kraemer, Xia Zhou, Devin Balkcom (Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies)