Dr Thomas Lidbetter

Visiting Senior Fellow

Department of Mathematics
London School of Economics

Houghton Street, London WC2A 2AE, United Kingdom
E-mail: t.r.lidbetter@lse.ac.uk

I am an associate professor in the Department of Management Science and Information Systems at Rutgers Business School.

Research Interests

Search theory and algorithms, game theory, discrete optimisation, scheduling, mathematical biology.

Awards and funding

2023-2026: AFOSR award for “A Polyhedral Approach to some Infinite Sequencing Problems” (award number FA9550-23-1-0556)

2019-2022: NSF award for “Continuous Search and Patrolling on Networks” (award number 1935826)

2019-2022: NSF award for “Collaborative Research: Minimum-cost strategies for Sequential Search and Evaluation” (award number 1909446), with Lisa Hellerstein

2019 Rutgers Business School Junior Faculty Research Excellence Award

2016 LSE Teaching and Learning Centre Teaching Prize

2013 Doctoral Dissertation Award for the most distinguished body of research leading to a doctorate in the field of Operational Research, from UK OR Society

2013 Mathematics Class Teacher Prize, LSE Department of Mathematics

Education

2009-2013, PhD in Department of Mathematics, LSE

PhD supervisor: Steve Alpern

Second supervisor: Bernhard von Stengel

Thesis: Hide-and-seek and other Search Games

2007-2009, MSc in Operational Research, LSE

2004-2005, MMath in Mathematics, University of Cambridge

2001-2004, MA in Mathematics, University of Cambridge

Journal Articles

Bui T, Lidbetter T and Lin, K (2023) Optimal pure strategies for a discrete search game, European Journal of Operational Research (in press)

Lidbetter T and Xie Y (2023) The search and rescue game on a cycle, Theoretical Computer Science, https://doi.org/10.1016/j.tcs.2023.114016

Bui T and Lidbetter T (2023) Optimal patrolling strategies for trees and complete networks, European Journal of Operational Research, 311(2):769-776

Hellerstein L and Lidbetter T (2023) A game theoretic approach to a problem in polymatroid maximization, European Journal of Operational Research, 305(2):979-988

Alpern S, Bui T, Lidbetter T and Papadaki K (2022) Continuous patrolling games, Operations Research, 70(6):3076-3089

Happach F, Hellerstein L and Lidbetter T (2021) A general framework for approximating min sum ordering problems, INFORMS Journal on Computing, 34(3):1437-1452

Angelopoulos S and Lidbetter T (2020) Competitive search in a network, European Journal of Operational Research, 286(2):781-790

Agnetis A and Lidbetter T (2020) The largest-Z-ratio-first algorithm is 0.8531-approximate for scheduling unreliable jobs on m parallel machines, Operations Research Letters, 48(4):405-409

Lidbetter T and Lin KY (2020) A search game on a hypergraph with booby traps, Theoretical Computer Science, 821:57-70

Lidbetter T (2020) Search and rescue in the face of uncertain threats, European Journal of Operational Research, 285(3):1153-1160

Alpern S and Lidbetter T (2020) Search and delivery man problems: when are depth-first paths optimal?, European Journal of Operational Research, 285(3):965-976

Fokkink R, Lidbetter T and Végh L (2019) On submodular search and machine scheduling, Mathematics of Operations Research, 44(4):1145-1509

Hellerstein L, Lidbetter T and Pirutinsky D (2019) Solving zero-sum games using best response oracles with applications to search games, Operations Research, 67(3):731-743

Lidbetter T and Lin KY (2019) Searching for multiple objects in multiple locations, European Journal of Operational Research, 278(2):709-720

Angelopoulos S, Dürr C and Lidbetter T (2019) The expanding search ratio of a graph, Discrete Applied Mathematics, 260:51-65

Alpern S, Lidbetter T and Papadaki K (2019) Optimizing periodic patrols against short attacks on the line and other networks, European Journal of Operational Research, 273(3):1065-1073

Alpern S and Lidbetter T (2019) Approximate solutions for expanding search on general networks, Annals of Operations Research, 275(2):259-279

Bonato A and Lidbetter T (2019) Bounds on the burning numbers of spiders and path-forests, Theoretical Computer Science, 794:12-19

Lidbetter T (2017) On the approximation ratio of the random Chinese postman tour for network search, European Journal of Operational Research 263(3):782-788

Papadaki, K., Alpern, S., Lidbetter, T. and Morton, A. (2016) Patrolling a border, Operations Research 64(6):1256-1269

Csóka E and Lidbetter T (2016) The solution to an open problem for a caching game. Naval Research Logistics 63(1):23-31

Lidbetter T (2015) A caching game with infinitely divisible hidden material. SIAM Journal on Control and Optimization 52(5):3040-3056

Alpern S and Lidbetter T (2015) Optimal trade-off between speed and acuity when searching for a small object. Operations Research 63(1):122-133

Alpern S and Lidbetter T (2014) Searching a variable speed network. Mathematics of Operations Research, 39(3):697-711

Lidbetter T (2013) Search games with multiple hidden objects. SIAM Journal on Control and Optimization 51(4):3056–3074

Alpern S and Lidbetter T (2013) Mining coal or finding terrorists: the expanding search paradigm. Operations Research, 61(2):265-279

Alpern S, Fokkink R, Lidbetter T and Clayton N (2012) A search game model of the scatter hoarder's problem. Journal of the Royal Society Interface, 9(70):869-879

Working papers

Alpern S and Lidbetter T (2023) Searching a tree with signals: routing mobile sensors for targets emitting radiation, chemicals or scents (in review)

Book Chapters

Lidbetter T (2013) Search Games for an Immobile Hider. Fokkink R et al. (ed.) Search Theory: A Game Theoretic Approach

Conference Proceedings

Hellerstein L, Lidbetter T and Witter TA (2022) Local Search Algorithm for the Min-Sum Submodular Cover Problem. In The 33rd International Symposium on Algorithms and Computation (ISAAC 2022) (accepted)

Alpern S, Lidbetter T, Morton A and Papadaki K (2016) Patrolling a Pipeline. In International Conference on Decision and Game Theory for Security 2016, 129-138, Springer International Publishing.

Angelopoulos S, Dürr C and Lidbetter T (2016) The expanding search ratio of a graph. In The 33rd International Symposium on Theoretical Aspects of Computer Science (STACS), 2016.

Alpern S, Fokkink R, Op Den Kelder J and Lidbetter T (2010) Disperse or unite? A mathematical model of coordinated attack.  In Decision and Game Theory for Security - First International Conference, GameSec 2010, Berlin, Germany, November 22-23, 2010. Proceedings; 01/2010

Previous employment

2013-2016, LSE Fellow

2011-2013, Graduate teaching assistant, LSE

2009-2011, Operational Research Analyst, Home Office (UK Civil Service)