Alexander Erreygers

I am a postdoctoral researcher at Ghent University, more precisely at the Foundations Lab for imprecise probabilities (FLip) of the Department of Electronics and Information Systems, part of the Faculty of Engineering and Architecture.

All of my research is situated in the theory of imprecise probabilities. Within this theory, my main topic of interest is uncertain processes. I’ve worked extensively on the continuous-time finite-state case, and am currently still working on dealing with infinite state spaces in combination with continuous time—with the odd excursion to the setting of discrete time once in a while. Other topics of interest, amongst others and either current or past, are choice funtions and quantum mechanics.

If interested, you can scroll down to take a look at my scientific output, brief academic CV or contact details.

Scientific output

Journal articles

1. Arne Decadt, Alexander Erreygers & Jasper De Bock. Extending choice assessments to choice functions: An algorithm for computing the natural extension. In International Journal of Approximate Reasoning, 178:109331, Mar. 2025.
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   • doi: 10.1016/j.ijar.2024.109331
2. Alexander Erreygers. Convex expectations for countable-state uncertain processes with càdlàg sample paths. In International Journal of Approximate Reasoning, 175:109308, Oct. 2024.
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   • doi: 10.1016/j.ijar.2024.109308
3. Alexander Erreygers & Jasper De Bock. Markovian imprecise jump processes: Extension to measurable variables, convergence theorems and algorithms. In International Journal of Approximate Reasoning, 147:78–124, Aug. 2022.
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   • doi: 10.1016/j.ijar.2022.05.006
4. Alexander Erreygers & Enrique Miranda. A graphical study of comparative probabilities. In Journal of Mathematical Psychology, 104:102582, Sep. 2021.
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   • doi: 10.1016/j.jmp.2021.102582
5. Alexander Erreygers & Jasper De Bock. Bounding inferences for large-scale continuous-time Markov chains: A new approach based on lumping and imprecise Markov chains. In International Journal of Approximate Reasoning, 115:96–133, Dec. 2019.
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   • doi: 10.1016/j.ijar.2019.09.003
6. Alexander Erreygers, Jasper De Bock, Gert de Cooman & Arthur Van Camp. Optimal control of a linear system subject to partially specified input noise. In International Journal of Robust and Nonlinear Control, 29(12):3892–3914, Aug. 2019.
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   • doi: 10.1002/rnc.4583
7. Alexander Erreygers, Cristina Rottondi, Giacomo Verticale & Jasper De Bock. Imprecise Markov Models for Scalable and Robust Performance Evaluation of Flexi-Grid Spectrum Allocation Policies. In IEEE Transactions on Communications, 66(11):5401–5414, Nov. 2018.
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   • doi: 10.1109/TCOMM.2018.2846235
   • arXiv: 1801.05700

Conference articles

1. Yema Paul, Alexander Erreygers & Jasper De Bock. Expected time averages in Markovian imprecise jump processes: A graph-theoretic characterisation of weak ergodicity. In the proceedings of the 13th International Symposium on Imprecise Probability: Theories and Applications (ISIPTA 2023), Jul. 2023.
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2. Alexander Erreygers. Sublinear expectations for countable-state uncertain processes. In the proceedings of the 13th International Symposium on Imprecise Probability: Theories and Applications (ISIPTA 2023), Jul. 2023.
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   • arXiv: 2301.10066
3. Arne Decadt, Alexander Erreygers, Jasper De Bock & Gert de Cooman. Decision-making with E-admissibility given a finite assessment of choices. In the proceedings of the 10th International Conference on Soft Methods in Probability and Statistics (SMPS 2022), Aug. 2022.

   Winner of a Gold International Journal of Approximate Reasoning Best Paper Award.

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   • doi: 10.1007/978-3-031-15509-3_13
   • arXiv: 2204.07428
4. Alexander Erreygers & Jasper De Bock. Extending the domain of imprecise jump processes from simple variables to measurable ones. In the proceedings of the 12th International Symposium on Imprecise Probability: Theories and Applications (ISIPTA 2021), Jul. 2021.
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5. Jasper De Bock, Alexander Erreygers & Thomas Krak. Sum-product laws and efficient algorithms for imprecise Markov chains. In the proceedings of the 37th Conference on Uncertainty in Artificial Intelligence (UAI 2021), Jun. 2021.
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6. Alexander Erreygers & Enrique Miranda. A study of the set of probability measures compatible with comparative judgements. In the proceedings of the 18th International Conference on Information Processing and Management of Uncertainty in Knowledge-Based Systems (IPMU 2020), Jun. 2020.
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   • doi: 10.1007/978-3-030-50143-3_13
7. Alexander Erreygers & Jasper De Bock. First steps towards an imprecise Poisson process. In the proceedings of the 11th International Symposium on Imprecise Probability: Theories and Applications (ISIPTA 2019), Jun. 2019.
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   • arXiv: 1905.05734
8. Thomas Krak, Alexander Erreygers & Jasper De Bock. An Imprecise Probabilistic Estimator for the Transition Rate Matrix of a Continuous-Time Markov Chain. In the proceedings of the 9th International Conference on Soft Methods in Probability and Statistics (SMPS 2018), Sep. 2018.
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   • doi: 10.1007/978-3-319-97547-4_17
   • arXiv: 1804.01330
9. Alexander Erreygers & Jasper De Bock. Computing Inferences for Large-Scale Continuous-Time Markov Chains by Combining Lumping with Imprecision. In the proceedings of the 9th International Conference on Soft Methods in Probability and Statistics (SMPS 2018), Sep. 2018.

   Winner of the International Journal of Approximate Reasoning Best Paper Award.

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   • doi: 10.1007/978-3-319-97547-4_11
   • arXiv: 1804.01020
10. Alexander Erreygers & Jasper De Bock. Imprecise continuous-time Markov chains: Efficient Computational methods with guaranteed error bounds. In the proceedings of the 10th International Symposium on Imprecise Probability: Theories and Applications (ISIPTA'17), Jul. 2017.
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    • arXiv: 1702.07150

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Talks and posters

1. Alexander Erreygers. Imprecise-probabilistic processes – part I. Lecture at the 2024 SIPTA School, 15 Aug. 2024. Part II by Michael Kupper.
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2. Jasper De Bock & Alexander Erreygers. How to make your Markov chains robust: An imprecise probabilities perspective. Invited talk at the Operations Planning Accounting & Control Seminar, Eindhoven University of Technology, 21 Sep. 2023.
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3. Alexander Erreygers. One way to define an imprecise-probabilistic version of the Poisson process. Invited talk for the SIPTA Seminar series, 16 Jun. 2023.
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4. Alexander Erreygers. Imprecise (Markovian) processes: Beyond finitary variables. Presented at the Workshop on Imprecise Probability and Robust Finance (ImPRooF), 20 Sep. 2022.
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5. Alexander Erreygers. Markoviaanse imprecieze sprongprocessen: grondslagen, algoritmen en toepassingen. Presenstation (in Dutch) for the final round of the `AIG-prijs', 2 Jun. 2022.
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6. Alexander Erreygers. Extending the domain of Markovian imprecise jump processes. Presented at the International Conference on Uncertainty Quantification & Optimisation (UQOP 2020), 17 Nov. 2020.
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7. Alexander Erreygers. Imprecise stochastic processes. Invited talk at the University of Oviedo, 11 Nov. 2019.
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8. Alexander Erreygers & Jasper De Bock. Computing limit expectations of imprecise continuous-time Markov chains. Presented at the 11th Workshop on Principles and Methods of Statistical Inference with Interval Probability (WPMSIIP 2018), 1 Aug. 2018.
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9. Alexander Erreygers & Jasper De Bock. Lumping continuous-time Markov chains. Presented at the 10th Workshop on Principles and Methods of Statistical Inference with Interval Probability (WUML/WPMSIIP 2017), 12 Sep. 2017.
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10. Alexander Erreygers & Jasper De Bock. Towards an imprecise Poisson process. Presented at the 10th Workshop on Principles and Methods of Statistical Inference with Interval Probability (WUML/WPMSIIP 2017), 12 Sep. 2017.
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Edited volumes

1. Proceedings of the Fourteenth International Symposium on Imprecise Probabilities: Theories and Applications. Edited by Sébastien Destercke, Alexander Erreygers, Max Nendel, Frank Riedel & Matthias C. M. Troffaes. Proceedings of Machine Learning Research vol. 290 , PMLR, Jul. 2025.
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Preprints / work in progress

1. Jasper De Bock, Alexander Erreygers & Floris Persiau. A convenient characterisation of convergent upper transition operators.
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   • arXiv: 2502.04509
2. Alexander Erreygers. Uniformly continuous semigroups of sublinear transition operators.
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3. Alexander Erreygers & Jasper De Bock. Countable-state stochastic processes with càdlàg sample paths.
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   • arXiv: 2301.07992

Doctoral dissertation

1. Alexander Erreygers. Markovian Imprecise Jump Processes: Foundations, Algorithms and Applications. Doctoral dissertation submitted to obtain the academic degree of Doctor of Mathematical Engineering, Ghent University, 16 Sep. 2021.

   Supervisors: Jasper De Bock, Gert de Cooman & Herwig Bruneel..

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Academic CV

Working experience

Awards

Teaching