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


I am an EPSRC Fellow in the Department of Pure Mathematics and Mathematical Statistics (DPMMS) at the University of Cambridge (recently returned from 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. I also spent an interlude during the pandemic engaged in epidemiological research (see below).

My PhD 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 spent most of March 2020-April 2022 engaged in a combination of fact checking, science communication, advocacy, scientific correspondence, and mathematical epidemiology research related to the pandemic.

I initially focussed on fact checking and evaluating the appropriateness of individual study designs and data analysis methods in different contexts as I learned more about epidemiology, infectious disease, and public health. Prior to widespread vaccine availability and uptake in the UK, I also advocated for increased freedoms and protections for clinically vulnerable and immunochallenged members of the population in England, including the right to flexible school arrangements for families with clinically vulnerable household members--a cause later taken up by the Public Law Centre and by Good Law Project. From there, my advocacy focus shifted to accuracy in risk/benefit analyses of vaccine strategies, improved access to (and uptake of) vaccines, and getting the most out of rapid antigen test strategies.

From a research standpoint, I have been interested in study design and data analysis methods, the role of paediatric and other subpopulations in transmission dynamics, and the impact of variants on various aspects of epidemic impact and policy response.

Public Engagement
-Twitter account, @SarahDRasmussen (Has received informal recognition).
-22 Dec 2021, Times Radio interview on Omicron-related questions.
-2 Feb 2021, invited panelist for an All-Party Parliamentary Group on Coronavirus session on school measures and child transmission.

Preprints, Publications, Selected Correspondence + Fact Checking
"Relative generation time distribution and relative reproduction number for Omicron versus Delta variants of SARS-CoV-2 from England case incidence"
(In preparation)

"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. (Haven't got around to submitting to a journal yet.) >

w/ Deepti Gurdasani, Athena Akrami, Valerie C Bradley, Anthony Costello, et al,
"Long COVID in children",
The Lancet Child & Adolescent Health, Vol 6 (1), E2, 01 Jan 2022.

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, Vol 397 (10280), p1177-1178, 27 Mar 2021.

"Ed Humpherson to Iain Bell: ONS COVID-19 Infection Survey ad hoc teacher analysis"
(A letter from the Director of the Office for Statistics Regulation in response to a report I submitted.)

"Violations of stated methodology and misreported results in Viner and colleagues' School Closures Review"
May 2020. See further details and explanation here and a summary thread here.


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.

"L-spaces, taut foliations, and 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.)