AutumnTHE OLYMPIAD COLLECTION
Menu
RESEARCHED WITH AUTUMN
LJ

Lim Jeck

Mathematician (discrete geometry, additive combinatorics); 5-time IMO medalist for Singapore
University of Oxford · Oxford, United Kingdom · academic
LinkedIn · limjeck.com
sites.google.com
Details
LocationOxford, United Kingdom
Company siteox.ac.uk
UniversityUniversity of Cambridge
discrete geometryadditive combinatoricscombinatoricsmathematics
Notes
  • Quant employment verification: CONFIRMED. His own website and CV document a quantitative-researcher internship at Jane Street New York, May-Aug 2018; Jane Street is a proprietary trading firm and a leading market maker in equities, bonds, ETFs and options, so this is a genuine quantitative-finance internship by a confirmed identity (5-time Singapore IMO contestant, NUS High, Cambridge, Caltech). No other quant-finance employment (bank, asset manager, energy or crypto trading) appears on any source, and no quant role is claimed after 2018.Aug 1, 2018
  • Career after the PhD runs through pure-math academia only: Postdoctoral Research Associate in Combinatorics at the University of Oxford (2025-2026, expected), then a Hausdorff Postdoc at the University of Bonn from Fall 2026 - no quant-finance role appears after the 2018 Jane Street internship.Sep 1, 2026
  • PhD in Mathematics at Caltech (2020-2025) advised by David Conlon; dissertation work in discrete geometry and additive combinatorics, awarded the Scott Russell Johnson Graduate Dissertation Prize in 2025 (US$1,000) after the same prize for Excellence in Graduate Study in 2022.Jun 1, 2025
  • Represented Singapore at the IMO in five consecutive years 2009-2013 (bronze 2009, silver 2010, gold 2011, gold 2012, gold 2013); in 2012 he scored a perfect 42, the only perfect score that year. Recorded on his own site and the IMO official contestant page.Jul 28, 2013
  • Public contact is his institutional Oxford address [contact omitted], listed on his own CV, alongside a personal site and a Google Sites academic page; research correspondence goes through the Oxford Mathematical Institute.Jan 1, 2026
  • Interned at Jane Street New York as a Quantitative Researcher, May-Aug 2018, between his Cambridge BA and MMath years; this is the single quant-finance employment datapoint, and it sits a year before his Caltech PhD, after which he stayed in pure-math academia.Aug 1, 2018
  • Also won IPhO 2013 gold (Copenhagen), a rare IMO+IPhO double in the same year; he is a two-discipline olympiad medalist, not only a mathematician.Jul 15, 2013
  • Research focus is discrete geometry and additive combinatorics; publications span sum-free subsets, Freiman dimension, sums of dilates/linear transformations, differences of harmonic numbers, and evasive sets, mostly with David Conlon and increasingly with Peter Keevash, Cosmin Pohoata, Jiaxi Nie and Ji Zeng.Jan 1, 2026
  • Solved the Kupitz planar discrepancy problem for pseudolines with David Conlon (2023), a result notable enough to be written up on Gil Kalai's blog; the published version appeared in Advances in Mathematics 480 (2025).Aug 11, 2023
  • Returned to the IMO as Coordinator in 2019, 2023 and 2024 and as Trainer cum Observer in 2016 (Singapore team 4th); he remains embedded in the Singapore olympiad training scene years after competing.Jul 22, 2024
  • Alibaba Global Mathematics Competition record: Bronze 2021, Merit 2022, Merit 2023, then Silver 2024 (US$15,000) in the Combinatorics and Probability track - a sustained top-tier placing in a global research-level contest.Jun 1, 2024
  • Undergraduate and MMath at Trinity College, Cambridge (2016-2020): BA (hons) Mathematics, ranked 4th in Part II (2019), then MMath with Distinction (Part III, 96%) in 2020; held a Senior Scholarship in 2017, 2018 and 2019.Jun 1, 2020

Competition record

Singapore · IMO

Related collections

Explore the collection
More from SingaporeView all