Christian Igel

Professor, Dr. habil.

Office address:		Mail address:
Department of Computer Science		Department of Computer Science
University of Copenhagen		University of Copenhagen
Universitetsparken 1, room 1.2.20		Universitetsparken 5
2100 København Ø		2100 København Ø

Email:	igel@diku.dk
Phone:	(+45) 21849673

Short CV

I am professor at DIKU, the Department of Computer Science at the University of Copenhagen. I studied Computer Science at the Technical University of Dortmund, Germany. In 2002, I received my Doctoral degree from the Faculty of Technology, Bielefeld University, Germany, and in 2010 my Habilitation degree from the Department of Electrical Engineering and Information Sciences, Ruhr-University Bochum, Germany. From 2003 to 2010, I was a Juniorprofessor for Optimization of Adaptive Systems at the Institut für Neuroinformatik, Ruhr-University Bochum. In October 2010, I was appointed professor with special duties in machine learning at DIKU. Since December 2014 I am a full professor at DIKU.

I am director of the SCIENCE AI Centre. You can find a short article about the centre here. Furthermore, I am a co-lead of the Pioneer Centre for Artificial Intelligence, Denmark.

I am a Fellow of ELLIS, European Lab for Learning and Intelligent Systems.

Among others, I serve as an advisory board member of the German Journal on Artificial Intelligence (KI) and an Associate Editor of the Evolutionary Computation Journal (ECJ).

Research Interests

My main research area is Machine Learning.

Currently, I am particularly interested in

support vector machines and other kernel-based methods,
evolution strategies for single- and multi-objective optimization and reinforcement learning,
PAC-Bayesian analysis of ensemble methods,
deep neural networks and stochastic neural networks,

and applications of machine learning that help achieve the sustainable development goals.

Selected Recent Publications

Please click here for a full list. I also maintain a Google scholar profile.

Carsten Bøcker Pedersen, Marianne Giørtz Pedersen, Sussie Antonsen, Emil Michael Pedersen, Henriette Thisted Horsdal, Jean-Christophe Debost, Preben Bo Mortensen, Liselotte Vogdrup Petersen, Bjarni J. Vilhjálmsson, Jørgen Feldbæk Nielsen, Jeppe Klok Due, Anders Søgaard, Christian Igel, Wesley K. Thompson, Chun Chieh Fan, Naomi R. Wray, John J. McGrath, and Esben Agerbo. Absolute and Relative Risks of Mental Disorders in Families: A comprehensive Danish Register-Based Study. The Lancet Psychiatry 12(8):590-599, 2025

Martin Brandt, Jerome Chave, Sizhuo Li, Rasmus Fensholt, Philippe Ciais, Jean-Pierre Wigneron, Fabian Gieseke, Sassan Saatchi, Compton J. Tucker, and Christian Igel. High-resolution sensors and deep learning models for tree resource monitoring. Nature Reviews Electrical Engineering 2:13-26, 2025

Dustin Wright, Christian Igel, Gabrielle Samuel, and Raghavendra Selvan. Efficiency is Not Enough: A Critical Perspective of Environmentally Sustainable. Communications of the ACM 68(7)62-69, 2025

Christian Igel. Smooth Min-Max Monotonic Networks. International Conference on Machine Learning (ICML), 2024

Bjørn Leth Møller, Christian Igel, Kristoffer Knutsen Wickstrøm, Jon Sporring, Robert Jenssen, and Bulat Ibragimov. Finding NEM-U: Explaining unsupervised representation learning through neural network generated explanation masks. International Conference on Machine Learning (ICML), 2024

Florian Reiner, Martin Brandt, Xiaoye Tong, David Skole, Ankit Kariryaa, Philippe Ciais, Andrew Davies, Pierre Hiernaux, Jerome Chave, Maurice Mugabowindekwe, Christian Igel, Stefan Oehmcke, Fabian Gieseke, Sizhuo Li, Siyu Liu, Sassan S. Saatchi, Peter Boucher, Jenia Singh, Simon Taugourdeau, Morgane Dendoncker, Xiao-Peng Song, Ole Mertz, Compton Tucker, and Rasmus Fensholt. More than one quarter of Africa’s tree cover found outside areas previously classified as forest. Nature Communications 14, 2023

Compton Tucker, Martin Brandt, Pierre Hiernaux, Ankit Kariryaa, Kjeld Rasmussen, and Jennifer Small, Christian Igel, Florian Reiner, Katherine Melocik, Jesse Meyer, Scott Sinno, Eric Romero, Erin Glennie, Yasmin Fitts, August Morin, Jorge Pinzon, Devin McClain, Paul Morin, Claire Porter, Shane Loeffle, Laurent Kergoat, Bil-Assanou Issoufou, Patrice Savadogo, Jean-Pierre Wigneron, Benjamin Poulter, Philippe Ciais, Robert Kaufmann, Ranga Myneni, Sassan Saatchi, and Rasmus Fensholt. Sub-continental scale carbon stocks of individual trees in African drylands. Nature 615:80-86, 2023

Maurice Mugabowindekwe, Martin Brandt, Jerome Chave, Florian Reiner, David Skole, Ankit Kariryaa, Christian Igel, Pierre Hiernaux, Philippe Ciais, Ole Mertz, Xiaoye Tong, Sizhuo Li, Gaspard Rwanyiziri, Thaulin Dushimiyimana, Alain Ndoli, Valens Uwizeyimana, Jens-Peter Lillesø, Fabian Gieseke, Compton Tucker, Sassan S. Saatchi, and Rasmus Fensholt. Nation-wide mapping of tree-level aboveground carbon stocks in Rwanda. Nature Climate Change 13:91-97, 2022

Yi-Shan Wu, Andrés R. Masegosa, Stephan S. Lorenzen, Christian Igel, and Yevgeny Seldin. Chebyshev-Cantelli PAC-Bayes-Bennett Inequality for the Weighted Majority Vote. Advances in Neural Information Processing Systems (NeurIPS), 2021

Martin Brandt, Compton J. Tucker, Ankit Kariryaa, Kjeld Rasmussen, Christin Abel, Jennifer Small, Jerome Chave, Laura Vang Rasmussen, Pierre Hiernaux, Abdoul Aziz Diouf, Laurent Kergoat, Ole Mertz, Christian Igel, Fabian Gieseke, Johannes Schöning, Sizhuo Li, Katherine Melocik, Jesse Meyer, Scott Sinno, Eric Romero, Erin Glennie, Amandine Montagu, Morgane Dendoncker, and Rasmus Fensholt. An unexpectedly large count of trees in the western Sahara and Sahel. Nature 587:78-82, 2020 popular science summary 10 remarkable discoveries from 2020

Mathias Perslev, Sune Darkner, Lykke Kempfner, Miki Nikolic, Poul Jørgen Jennum, and Christian Igel. U-Sleep: Resilient High-Frequency Sleep Staging. npj Digital Medicine 4, 2021

Steffen Czolbe, Oswin Krause, Ingemar Cox, and Christian Igel. A Loss Function for Generative Neural Networks Based on Watson's Perceptual Model. Advances in Neural Information Processing Systems (NeurIPS), 2020 source code video

Andrés R. Masegosa, Stephan S. Lorenzen, Christian Igel, and Yevgeny Seldin. Second Order PAC-Bayesian Bounds for the Weighted Majority Vote. Advances in Neural Information Processing Systems (NeurIPS), 2020

Mathias Perslev, Michael Hejselbak Jensen, Sune Darkner, Poul Jørgen Jennum, and Christian Igel. U-Time: A Fully Convolutional Network for Time Series Segmentation Applied to Sleep Staging. Advances in Neural Information Processing Systems (NeurIPS 2019), 2019 source code

Fabian Gieseke and Christian Igel. Training Big Random Forests with Little Resources. ACM SIGKDD Conference on Knowledge Discovery and Data Mining (KDD), pp. 1445-1454, ACM Press, 2018 source code

Jan Kremer, Fei Sha, and Christian Igel. Robust Active Label Correction. International Conference on Artificial Intelligence and Statistics (AISTATS), Proceedings of Machine Learning Research 84, 2018

Niklas Thiemann, Christian Igel, Olivier Wintenberger, and Yevgeny Seldin. A Strongly Quasiconvex PAC-Bayesian Bound. In S. Hanneke and L. Reyzin, eds.: Algorithmic Learning Theory (ALT), Proceedings of Machine Learning Research 76, pp. 466-492, 2017

Oswin Krause, Dídac R. Arbonès, and Christian Igel. CMA-ES with Optimal Covariance Update and Storage Complexity. Advances in Neural Information Processing Systems (NIPS), supplement, 2016

Ürün Dogan, Tobias Glasmachers, and Christian Igel. A Unified View on Multi-class Support Vector Classification. Journal of Machine Learning Research 17(45), pp. 1-32, 2016