Staff Profile
Dr David Seifert
Reader in Pure Mathematics
 Email: david.seifert@ncl.ac.uk
 Telephone: +44 (0)191 208 5882
 Address: School of Mathematics,
Statistics and Physics
Herschel Building
Newcastle University
Newcastle upon Tyne
NE1 7RU, United Kingdom
I am a member of the Pure Mathematics group in the School of Mathematics, Statistics and Physics. I chair the School's EDI Committee, and I oversee the School's mentoring scheme for postgraduate research students. I represent the UK on the managing committee of an EUfunded project on Mathematical Models for Interacting Dynamics on Networks (COST Action 18232), and I am a member of the London Mathematical Society and the European Mathematical Society. I have been a Fellow of the UK Higher Education Academy (Advance HE) since 2017.
Before arriving in Newcastle I was at the University of Oxford, most recently as a fellow of St John's College, and before that as an undergraduate and later graduate student at Hertford College and Balliol College, respectively. I completed my Habilitation at TU Dresden, Germany.
My area of research is operator theory, and I am particularly interested in the quantitative asymptotic behaviour of operator semigroups. My work combines elements of functional analysis, harmonic analysis and complex analysis, and it has applications in the study of energy decay of damped waves, in some areas of mathematical control theory and in the theory of iterative methods.
I recently coorganised the conference New Challenges in Operator Semigroups, which was held in St John's College, Oxford.
My work has received generous financial support from various sources, including the London Mathematical Society, the Heilbronn Institute for Mathematical Research, the Engineering and Physical Sciences Research Council and the European Cooperation in Science and Technology (COST).
I welcome enquiries from prospective Master's students, PhD students and postdocs in my area of expertise.
In the academic year 2022/23 I am teaching the following courses:
 Group Project  MAS3091
 Linear Analysis  MAS3702

Articles
 Dell'Oro F, Paunonen L, Seifert D. Optimal decay for a waveheat system with ColemanGurtin thermal law. Journal of Mathematical Analysis and Applications 2023, 518(2), 126706.
 Batty CJK, Seifert D. Some developments around the KatznelsonTzafriri theorem. Acta Scientiarum Mathematicarum 2022. In Press.
 Batty CJK, Seifert D. A KatznelsonTzafriri theorem for analytic Besov functions of operators. Journal of Operator Theory 2022. In Press.
 Batty CJK, Seifert D. A continuousparameter KatznelsonTzafriri theorem for algebras of analytic functions. Studia Mathematica 2022, Epub ahead of print.
 Chill R, Paunonen L, Seifert D, Stahn R, Tomilov Y. Nonuniform stability of damped contraction semigroups. Analysis & PDE 2021. In Press.
 Chill R, Seifert D, Tomilov Y. Semiuniform stability of operator semigroups and energy decay of damped waves. Philosophical Transactions A 2020, 378(2185), 20190614.
 Ng ACS, Seifert D. Optimal rates of decay in the KatznelsonTzafriri theorem for operators on Hilbert spaces. Journal of Functional Analysis 2020, 279(12), 108799.
 Ng ACS, Seifert D. Optimal energy decay in a onedimensional waveheat system with infinite heat part. Journal of Mathematical Analysis and Applications 2020, 482(2), 123563.
 Hibble SJ, Chippindale AM, Zbiri M, Rees NH, Keeble DS, Wilhelm H, d'Abrumenil S, Seifert D. Intra and Interchain Interactions in (Cu_{1/2}Au_{1/2})CN, (Ag_{1/2}Au_{1/2})CN, and (Cu_{1/3}Ag_{1/3}Au_{1/3})CN and Their Effect on One, Two, and ThreeDimensional Order. Inorganic Chemistry 2020, 59(16), 11704–11714.
 Paunonen L, Seifert D. Asymptotics and approximation of large systems of ordinary differential equations. Systems & Control Letters 2020, 140, 104703.
 Debruyne G, Seifert D. Optimality of the quantified InghamKaramata theorem for operator semigroups with general resolvent growth. Archiv der Mathematik 2019, 113(6), 617–627.
 Rozendaal J, Seifert D, Stahn R. Optimal rates of decay for operator semigroups on Hilbert spaces. Advances in Mathematics 2019, 346, 359388.
 Batty CJK, Paunonen L, Seifert D. Optimal energy decay for the waveheat system on a rectangular domain. SIAM Journal on Mathematical Analysis 2019, 51(2), 808819.
 Paunonen L, Seifert D. Asymptotics for periodic systems. Journal of Differential Equations 2019, 266(11), 71527172.
 Debruyne G, Seifert D. An abstract approach to optimal decay of functions and operator semigroups. Israel Journal of Mathematics 2019, 233(1), 439451.
 MokhtarKharroubi M, Seifert D. Rates of convergence to equilibrium for collisionless kinetic equations in slab geometry. Journal of Functional Analysis 2018, 275(9), 24042452.
 Paunonen L, Seifert D. Asymptotic behaviour of coupled systems in discrete and continuous time. Journal of Dynamics and Differential Equations 2018, 30(2), 433444.
 Badea C, Seifert D. Quantified asymptotic behaviour of Banach space operators and applications to iterative projection methods. Pure and Applied Functional Analysis 2017, 2(4), 585598.
 Darwin O, Jha A, Roy S, Seifert D, Steele R, Stigant L. Nonoptimality of the Greedy Algorithm for subspace orderings in the method of alternating projections. Results in Mathematics 2017, 72(1), 979990.
 Paunonen L, Seifert D. Asymptotics for infinite systems of differential equations. SIAM Journal on Control and Optimization 2017, 55(2), 11531178.
 Paunonen L, Seifert D. Asymptotic behaviour in the robot rendezvous problem. Automatica 2017, 79, 127130.
 Badea C, Seifert D. Ritt operators and convergence in the method of alternating projections. Journal of Approximation Theory 2016, 205, 133148.
 Seifert D. Rates of decay in the classical KatznelsonTzafriri theorem. Journal d'Analyse Mathématique 2016, 130(1), 329354.
 Chill R, Seifert D. Quantified versions of Ingham’s theorem. Bulletin of the London Mathematical Society 2016, 48(3), 519532.
 Batty CJK, Paunonen L, Seifert D. Optimal energy decay in a onedimensional coupled waveheat system. Journal of Evolution Equations 2016, 16(3), 649–664.
 Seifert D. Some improvements of the KatznelsonTzafriri theorem on Hilbert space. Proceedings of the American Mathematical Society 2015, 143, 38273838.
 Seifert D. A quantified Tauberian theorem for sequences. Studia Mathematica 2015, 227, 183192.
 Seifert D. A Katznelson–Tzafriri Theorem for Measures. Integral Equations and Operator Theory 2015, 81(2), 255–270.

Conference Proceedings (inc. Abstracts)
 Dell'Oro F, Seifert D. A short elementary proof of the GearhartPrüss theorem for bounded semigroups. In: Control & Inverse Problems. 2022, Springer Nature. In Press.
 Paunonen L, Seifert D. Asymptotic behaviour of platoon systems. In: 22nd International Symposium on Mathematical Theory of Networks and Systems. 2016, Minnesota, MN, USA.