Sarah Rasmussen

Centre for Mathematical Sciences
Wilberforce Road
Cambridge CB3 0WB, UK

September 2020 - July 2021:
Institute for Advanced Study
1 Einstein Dr
Princeton, NJ 08540

(Non-pandemic times) Research

I am an EPSRC Fellow in the Department of Pure Mathematics and Mathematical Statistics (DPMMS) at the University of Cambridge (temporarily on leave September 2020-July 2021, for a sabbatical fellowship at the Institute for Advanced Study at Princeton). As a low-dimensional topologist, I study relationships among Heegaard Floer theory and various non-gauge-theoretic structures in 3 and 4 dimensions, such as left-invariant fundamental group orders, taut foliations, tight contact structures, and complex surface singularities.

My PhD (Harvard) is in mathematics but I have bachelors' degrees both in mathematics and in physics, I deferred my admission at Harvard's math PhD program to spend a year in Stanford's theoretical physics PhD program, and before that I had both some undergraduate training and an NSF REU internship in biomedical engineering. My earlier mathematical-physics training was in mirror symmetry and string theory, and I am still a fan of both.


I have spent most of the past year studying questions related to Covid-19, with an emphasis on children and schools, and often with an emphasis on checking scientific literature, media reports, and government-sponsored studies from a logical and quantitative point of view.

My first formal work in this respect was post-publication criticism of a Lancet Child & Adolescent Health systematic review on school closures led by SAGE member and RCPCH president Russell Viner. Here's a site archiving my academic work on this subject, and a thread summarising this work.

I submitted a report to the Office for Statistics Regulation about an ONS ad hoc study that mischaracterised teacher risk. Here is a thread summarising problems, plus a more detailed one. The OSR upheld my complaint.

On 2 February I addressed the All-Party Parliamentary Group on Coronavirus as part of a 3-person panel on schools and children.

COVID-19 Preprints and Publications

"A convergence based assessment of relative differences in age-stratified susceptibility and infectiousness for SARS-CoV-2 variants of B.1.1.7 lineage",
March 2021. (medRxiv preprint)

w/ Deepti Gurdasani, Nisreen A Alwan, Trisha Greenhalgh, Zoe Hyde, et al,
"School reopening without robust COVID-19 mitigation risks accelerating the pandemic",
The Lancet, 10 March 2021,


An action plan for pan-European defence against new SARS-CoV-2 variants, The Lancet, Feb 2021. (original signatory)
Call for pan-European commitment for rapid and sustained reduction in SARS-CoV-2 infections, The Lancet, Jan 2021. (original signatory)
John Snow Memo, Lancet version, Oct 2020. (late signatory)


2018-19 Part III 3-manifolds (Lent).
2017-18 Part III 3-manifolds.
2016-17 Part III Differential Geometry: Examples Classes.
2015-16 Part II Algebraic Geometry: Supervisions.

Invited Talks

Regensburg, Germany (remotely): Low-dimensional geometry and topology seminar, 24 Nov 2020.
UC Davis, CA, USA (remotely): Geometry/Topology Seminar, 13 Oct 2020.
Warwick, UK (remotely): Geometry & Topology Seminar, 4 Aug 2020.
Oberwolfach, Germany: Low-dimensional Topology, 16-22 Feb 2020. --- Quanta Magazine article on this conference (spot my arm holding a yellow die :) )
Oxford, UK: Low dimensional topology workshop, 6-10 January 2020.
Monash University, Australia: Topology Seminar, 16 October 2019.
Providence, USA (as co-organizer): ICERM Perspectives on Dehn Surgery, 15-19 July 2019.
Athens, GA, USA: 2019 Georgia Topology Conference, 22-26 May 2019.
Santa Barbara, CA, USA: KITP Quantum Knot Invariants and Supersymmetric Gauge Theories, 13-21 Nov 2018.
Regensburg, Germany: Workshop on Gauge theory and topological applications, 23-27 July 2018.
Princeton University, USA: Mini-conference on low-dimensional topology, 20-22 June 2018.
Dubrovnik, Croatia: Geometric structures on 3 and 4 manifolds, 11-15 June 2018.
Oxford University, UK: Topology Seminar, 4 June 2018.
Montréal, Canada: Perspectives on bordered Heegaard Floer theory school, 8-11 May 2018.
Montréal, Canada: Simons CRM Invited Scholar in Residence 1 Apr - 30 May 2018.
Aspen, CO, USA: Physics cafe: "Knots and physics" public outreach talk, 7 Mar 2018.
Aspen, CO, USA: Quantum knot homology and supersymmetric gauge theories conference, 4-10 Mar 2018.
Warwick, UK: Geometric topology in low dimensions workshop, 18-22 Sept 2017.
Braga, Portugal: XXVI International Fall Workshop on Geometry and Physics, 4-7 Sept 2017.
Oaxaca, Mexico: BIRS Thirty Years of Floer Theory for 3-Manifolds, 30 July - 4 Aug 2017.
Isle of Skye, UK: Low-dimensional topology on Skye, 12-16 June 2017.
Ludwig-Maximilians-Universität, Munich: Oberseminar Geometrie, 25 Apr 2017.
Georgia Tech & University of Georgia, USA: Joint Topology Seminar, 3 Apr 2017.
Washington University in St. Louis, USA: Colloquium and lecture series, 27-31 Mar 2017.
Rényi Insitute, Budapest: Algebraic Geometry and Differential Topology Seminar, 24 Feb 2017.
Newton Institute, UK: 3-Manifold Workshop, 30 Jan - 3 Feb 2017.
Durham University, UK: Pure Maths Colloquium, 21 Nov 2016.
Oberwolfach, Germany: Singularities Workshop, 25 Sept - 1 Oct 2016.
Glasgow, UK: 31st British Topology Meeting, 29-31 Aug 2016.
University of Oregon, USA: Topology/Geometry Seminar, 26 July 2016.
Dubrovnik, Croatia: Ronsfest: Perspectives in topology and geometry of 4-manifolds, 6-10 June 2016.
University of Glasgow, UK: Geometry and Topology Seminar, 1 Feb 2016.
University of Cambridge, UK: Differential Geometry and Topology Seminar, 27 May 2015.


Selected Publications

"Taut foliations and fundamental group left orders in Heegaard genus 2,"
Oberwolfach Reports: "Low-dimensional Topology," Workshop Report 2020, 8.

"Rational L-space surgeries on satellites by algebraic links,"
Journal of Topology 13 (4), 1333-1387, 2020.
doi:10.1112/topo.12162. arXiv:1703.06874.

"Taut foliations on graph manifolds," with Jonathan Hanselman, Jacob Rasmussen, and Liam Watson.
Compositio Mathematica, 156 (3), 604-612, 2020.

"Heegaard Floer theory, semigroups, and a new characterization of rational surface singularities,"
Oberwolfach Reports: “Singularities,” 13 (3), 2652-2655 (2016).

"L-space intervals for Graph Manifolds and Cables."
Compositio Mathematica, 153 (5), 1008-1049, 2017.
doi:10.1112/S0010437X16008319. arXiv:1511.04413.

"Floer Simple Manifolds and L-space Intervals," with Jacob Rasmussen.
Advances in Mathematics, 322 (2017) 738-805.
doi:10.1016/j.aim.2017.10.014. arXiv:1508.05900.


"A number theoretic result for Berge's conjecture,"
Harvard University PhD Thesis, 2009,
125 pp. ISBN: 978-1109-25330-6, ProQuest LLC, arXiv:1601.03430.
(2008-2014: career break for full-time parenting.
I didn't submit my first postdoc job application until 2014.)