Hi there! My name is Pachara but some people might know me as Akin. I am a fifth-year PhD student in the Theory Group at Princeton University. My advisor is Huacheng Yu . Prior to Princeton, I obtained a B.S. (in Mathematics and in Compute Science) and an M.Eng. (in Computer Science) from MIT where I was advised by Ronitt Rubinfeld .
email: [1stname] ๑ princeton dot edu | office: 35 Olden St #318b | [ scholar ]
CV available upon request
I am on the job market for positions starting in Summer or Fall 2027. Please reach out if you believe I will be a good fit!
Research I try to understand various foundations of algorithmic hardness and the interplay between them. This often includes areas such as communication complexity, information theory, as well as their extensions to data structure lower bounds. I also think about algorithms in models of computation with restricted access, e.g., query, communication, and streaming/sketching. Lately, I am intrigued by the complexity of composed functions. An Optimal Gap-Majority Lemma for Bounded-Round Communication [ pdf ] Pachara Sawettamalya The Communication Complexity of the Coin Problem [ pdf ] Adithya Diddapur, Pachara Sawettamalya SOSA 2027 Gap-Majority Lemmas in Communication Complexity [ pdf ] Pachara Sawettamalya, Huacheng Yu FOCS 2026 On the Communication Complexity of Maximum Matching and Negative-Weight Shortest Paths [ pdf ] Yu Cheng, Tianle Jiang, Pachara Sawettamalya , Huacheng Yu ESA 2026 A (Very) Nearly Optimal Sketch for k-Edge Connectivity Certificates [ pdf ] Pachara Sawettamalya , Huacheng Yu SOSA 2026 Minimum s-t Cuts with Fewer Cut Queries [ pdf ] [ talk@Brown ] Yonggang Jiang, Danupon Nanongkai , Pachara Sawettamalya SODA 2026 Strong XOR Lemma for Information Complexity [ pdf ] [ video ] Pachara Sawettamalya, Huacheng Yu STOC 2025 Near-Optimal Relative Error Streaming Quantile Estimation via Elastic Compactors [ pdf ] Elena Gribelyuk, Pachara Sawettamalya, Hongxun Wu, Huacheng Yu SODA 2025 Simple & Optimal Quantile Sketch: Combining Greenwald-Khanna with Khanna-Greenwald [ pdf ] Elena Gribelyuk, Pachara Sawettamalya, Hongxun Wu, Huacheng Yu PODS 2024 Fast Algorithms for Bounded-Range LIS Approximation [ pdf ] Pachara Sawettamalya Master Thesis 2022
Teaching At Princeton, I have been a TA for the following courses. COS 423 : Theory of Algorithms (Spring '26) COS 445 : Economics and Computation (Spring '24) COS 521 : Advanced Algorithms Design (Fall '23) At MIT, I was a TA/course staff for 6.045 ( Computability and Complexity Theory); 6.046 (Design and Analysis of Algorithms); 18.061 (Linear Algebra and Optimizations) ; 18.600 (Probability and Random Variables); 18.404 (Theory of Computation); 18.200 (Principles of Discrete and Applied Mathematics); 18.S097 (Proof Writing Workshop) ; 15.455x : ( Advanced Mathematics for Finance). On several occasions, I guest-lectured at Thailand's IMO p reparat ory camp.
Materials Over the years, I have had the opportunity to present both (1) my own work and (2) papers that I find interesting. I am sharing some of these (informal) notes here in case anyone finds them useful. Minimum s-t Cuts with Fewer Cut Queries [ slides ] A (Very) Nearly Optimal Sketch for k-Edge Connectivity Certificates [ slides ] Strong XOR Lemma for Information Complexity [ poster ] [ slides ] Parallel Repetition in Communication and Information [ slides ] Simple & Optimal Quantile Sketch: Combining Greenwald-Khanna with Khanna-Greenwald [ slides ] Information-to-Communication Compression Schemes A hn-Guha-McGregor Sketches [ notes ] Bipartite Matching in Communication Models [ notes ] , Matrix Multiplication and Seidel's Algorithm for APSP [ notes ] Bipartite Ramanujan Graphs of All Degree [ slides ]
Professional Activities Co-organizer for Princeton Theory Lunch (AY 25-26) Reviewer for flagship TCS journal and conferences 202 7 : ITC S, SODA, SOSA 2026: ESA, FOCS, ICALP, ISAAC, PODS, RANDOM, SODA 2025: FOCS 2024: FOCS Journal(s): SICOMP
Miscellaneous I was born and raised in Bangkok, Thailand. My name is pronounced Pa-cha-ra Sa-vet-ta-marn. Beyond academics, I enjoy playing poker, soccer and downhill skiing. Recently, I have also picked up recreational running. Here are some photos of my huge cat Pepper .