With success rates having been around 10-12% for years, things are never certain, but FNU has granted us another nice travel grant, which they have done continuously for more than 25 years. Kim Skak Larsen, together with Joan Boyar, Lene Favrholdt, and Kevin Schewior are looking forward to working on the many interesting ideas in the project, Trade-Offs for Algorithms Facing Uncertainty.

We are excited to welcome Lars Rohwedder as associate professor in the algorithms group. Lars is interested in approximation algorithms, parameterized algorithms, integer programming, and combinatorial problems in general. Lars got his Ph.D. from the University of Kiel in 2019. He has held a postdoc position at EPFL and a tenured assistant professorship at the School of Business and Economics, Maastricht University. We look forward to working with Lars!

Kevin Schewior attended the International Symposium on Mathematical Programming (ISMP), a triennial conference, arguably the most important conference on mathematical optimization. Talks were organized in 35 streams, and there were 19 invited speakers. The conference took place in Montreal, Canada. Kevin gave a talk on Stochastic Function Evaluation, which combined his results published in SIDMA in 2024 (with Benedikt Plank) and in the proceedings of ITCS 2024 (with Lisa Hellerstein and Naifeng Liu).

At the 1st Workshop on Security-Centric Strategies for Combating Information Disorder (SCID), held in conjunction with ACM AsiaCCS 2024 in Singapore, Simon Erfurth presented his latest results on maintaining authenticity under JPEG compressions. His talk, Digital Signatures for Authenticating Compressed JPEG Images, focused on the highlights of his single-authored paper, published as open access. Simon traveled to Singapore as a smaller part of his month-long visit to Academia Sineca in Taiwan.

Kevin Schewior and Lene Favrholdt, together with Marco Chiarandini from another IMADA section, organized the 16th MAPSP - the biennial workshop on models and algorithms for planning and scheduling problems, with Kevin as chair. The workshop was held in wonderful surroundings at Hotel Koldingfjord, June 23 - 28, 2024. Joan Boyar, Lene, and Kevin chaired a session each, and Kim Skak Larsen gave the talk Online Interval Scheduling with Predictions, and Kevin the talk Quickly Determining Who Won an Election. Finally, Magnus Berg gave a 5 min. talk on Online Minimum Spanning Trees with Weight Predictions and Lene one on Online Unit Profit Knapsack with Untrusted Predictions. The workshop was attended by around 100 researchers from all over the world, and the participants enjoyed a daily invited talk and contributed talks in two parallel sessions, but the organizers had also allocated large time slots for collaboration.

Kevin Schewior attended the Lorentz Center workshop on New challenges in search and patrolling games in Leiden, The Netherlands, organized by Spyros Angelopoulos (CNRS - the National Centre for Scientific Research, France), Thomas Lidbetter (Rutgers University), Katerina Papadaki (LSE - the London School of Economics and Political Science), and Florian Wagener (University of Amsterdam). About 25 researchers from the Computer Science and Operation Research community participated. The focus was on problems in which a mobile searcher must locate an adversarial hider within a given environment. Kevin gave a talk on Online search for a hyperplane in high-dimensional Euclidean space.

DTU organized this semester's ARCO (Algorithmic Research: Cooperation around Oresound), but they did so in the historical building of the Royal Danish Academy of Sciences and Letters. Magnus Berg, Joan Boyar, Kim Skak Larsen, Jørgen Bang-Jensen, and Bjarne Toft attended, while Lene Favrholdt gave the talk Online Unit Profit Knapsack with Predictions.

Kevin Schewior visited Lisa Hellerstein at the Tandon School of Engineering of New York University for about two months as part of his sabbatical. The visit started right after ITCS 2024, at which a paper co-authored by Lisa and Kevin was presented. In New York, they started several new projects on stochastic Boolean function evaluation, on which they are planning to continue in the next months. Kevin also gave a talk on recent advances in prophet inequalities in the NYU Theory Seminar, held jointly by the Courant Theoretical Computer Science Group and the Tandon Algorithms and Foundations Group.

Together with Kim Skak Larsen, Joan Boyar attended D³A - Danish Digitalization, Data Science and AI 1.0 at Nyborg Strand Hotel & Conference, where she gave the talk Paging with Succinct Predictions. The talk represented joint work with Kim as well as Lene M. Favrholdt, also from SDU, together with other researchers from different locations in Europe. The results had previously been presented at the 2023 ICML. Joan's gave her talk in the Trends in Algorithms Research in Denmark workshop on the first afternoon.

Simon Erfurth presented recent work on image authentication at the Half-day Conference on AI: Innovation, Transformation, and Deterioration, organized by the SDU Cluster on Creativity and Innovation in the Digital Age (CIDA), together with Johanna Eggers, both of whom are affiliated with DDC - the Digital Democracy Centre. Johanna gave the first motivational half of the presentation Securing News Authenticity: A Novel Approach for Combating Misinformation in the Age of Generative AI through Digital Signatures for Images, while Simon followed up in the second half with the more technical part of the contribution. There were many interested people in the audience asking questions, following the very clear but fairly brief presentation. Joan Boyar, one of Simon's advisors, also attended the conference.

The online algorithms group organized this fall's ARCO workshop. A record high number of participants (55 in all) signed up for the event. ARCO (Algorithmic Research: Cooperation around Øresund) is a network for exchanging research within algorithms and for promoting general interest in this research area within the Øresund Region (interpreted rather broadly).

It was a full day, starting at 9:30 with croissants and ending with pizzas at 17:30, with excellent talks and great interaction during coffee, lunch, and dinner breaks. All meals and refreshments were generously sponsored by DIREC.

Martin Böhm from the University of Wrocław visited Kevin Schewior for a week and worked with him in particular, but also with Joan Boyar, Lene Favrholdt, and Kim Skak Larsen from the online algorithms group. Martin gave a very well attended research seminar in the middle of the week, where he discussed interesting follow-up work to load balancing challenges from his dissertation.

This semester, we were excited to receive the first three TACsy Ph.D. students:

• Erika M. Herrera arrived from Spain with a bachelor degree in Mathematics from the University of La Laguna and a master's degree in Computational Engineering and Mathematics from the Open University of Catalonia.
• Lena Gladbach arrived from Germany with a master's degree in Computer Science from Leipzig University and a bachelor degree in Media Informatics from Leipzig University of Applied Sciences.
• Adittya Pal arrived from India with a master's degree in Integrated Management Information Systems with Chemistry from the National Institute of Science Education and Research, Bhubaneswar, Odisha, India.

The students are advised by Jakob Lykke Andersen, Rolf Fagerberg, and Daniel Merkle, in different combinations of who is the main advisor. They are all enrolled as cotutelle students with Peter Dittrich as the advisor at Friedrich-Schiller-University Jena.

They will work on projects in Algorithmic Cheminformatics, as outlined in the TACsy goals. TACsy is an acronym for Training Alliance for Computational Systems Chemistry, which obtained funding as a Marie-Skłodowska-Curie Joint Doctoral Network.

Ph.D. students Sissel Banke and Casper Asbjørn Eriksen from the Cheminformatics group each presented a paper at ISBRA - the International Symposium on Bioinformatics Research and Applications, held in Wrocław, Poland. Sissel presented the paper On the Realisability of Chemical Pathways, representing joint work with her advisors and others, based on Petri Nets. Casper presented recent work on the tool StructRecon, described in the paper Reconciling Inconsistent Molecular Structures from Biochemical Databases, representing joint work with his advisors. They enjoyed an interested audience in an intimate session of the conferences.

Simon Erfurth, Joan Boyar, and Kim Skak Larsen joined the 24-hour DDC meeting at the picturesque Hotel Vejlefjord. Among other activities, Simon updated the center members on the progress in his Ph.D. project.

Faith Ellen (an honorary professor at our department) from the University of Toronto visited Joan and Kim for a week, working on connections between their respective areas, now with a focus on distributed computing. This is a continuation of work initiated in Toronto during Joan's and Kim's visit there in May. During the weekend, the group found time to hike to Enebærodde.

Simon Erfurth presented his work on Quotable Signatures for Authenticating Shared Quotes on Latincrypt, October 4-6, 2023, at Universidad de las Fuerzas Armadas ESPE in Equador. His paper that represents joint work with his advisors Joan Boyar, Kim Skak Larsen, and Ruben Niederhagen has as focus to combat misinformation by bolstering authentic content on social media. This is facilitated by defining quotable signature schemes, which are digital signature schemes with the additional property that from the signature for a message, any party can extract signatures for (allowable) quotes from the message, without knowing the secret key or interacting with the signer of the original message.

On a recently published list of top researchers world wide, SDU has one mathematician listed: Anders Yeo from our Algorithms Section; see the listing from Research.com. Anders also appears on the computer science list.

The Algorithms Section is proud to have such a prolific and frequently cited researcher as a member of our group!

The algorithms section had three papers at the European Symposium on Algorithms (ESA), the European top conference on algorithms, which took place in Amsterdam, The Netherlands. The papers were A Parameterized Algorithm for Vertex Connectivity Survivable Network Design Problem with Uniform Demands (Jørgen Bang-Jensen, Kristine Vitting Klinkby, Pranabendu Misra, Saket Saurabh), Improved Approximation Algorithms for the Expanding Search Problem (Svenja Griesbach, Felix Hommelsheim, Max Klimm, Kevin Schewior), and Threshold Testing and Semi-Online Prophet Inequalities (Martin Hoefer, Kevin Schewior). Kevin Schewior attended the conference and gave the talk on prophet inequalities.

As of today, Kim Skak Larsen takes over as Head of the Algorithms Section from Daniel Merkle. As part of that, Kim enters the department's management group. Kim has expressed his gratitude towards Daniel for taking care of the group during the last three years. Daniel is moving to a new position at Bielefeld University, but fortunately stays associated with IMADA, and will still take full part in the exciting research projects the cheminformatics group are running. Kim is not new to managerial tasks, having been head of section before as well as head of department some years back. He is looking forward to working with and for this wonderful group of excellent researchers!

Joan Boyar was an invited speaker at this year's MFCS - the 48th International Symposium on Mathematical Foundations of Computer Science, held at the INP in Bordeaux, France. Joan introduced the audience to Online Algorithms with Predictions, a topic she has recently and naturally progressed into after her succesful endeavors in advice complexity.

Between the August 13 and August 20, Anders Yeo visited Nankai University in Tianjin, China, and Northwestern Polytechnical University in Xi'an, China. Anders gave the talk Transversals in hypergraphs and total domination in graphs at the Northwestern Polytechnical University.

Professor Gregory Gutin, from Royal Holloway, University of London, also visited these university at the same time, and Anders and Gregory initiated some new, interesting collaborations with Chinese colleagues at the above universities.

They also got to see the Terracotta Army in Xi'an!

Magnus Berg gave his first conference talk at the 18th Algorithms and Data Structures Symposium (WADS), which was held at Concordia University in Montreal. There were several interested researchers asking questions following the talk and many positive remarks later during the conference. The talk was based on the accepted paper, Online Minimum Spanning Trees with Weight Predictions, presenting joint work with Joan Boyar, Lene M. Favrholdt, and Kim S. Larsen.

Anders Yeo gave an invited talk, Directed Max-Cut and Some Generalizations, at the Graph Theory session of the 29th Nordic Congress of Mathematicians, July 3-7.

The Graph Theory session was organized by Bjarne Toft, emeritus in the Algorithms Section, and Michael Stiebitz, a frequent visitor to our department.

Anders Yeo gave one of the 11 plenary talks at the 10th Slovenian Conference on Graph Theory (also known as "the Bled Conference"). The conference was held in Kranjska Gora, Slovenia, June 18-24, and the title of the plenary talk was Directed Max-Cut and Some Generalizations. The conference is one of the largest graph theory conferences in the world with over 300 participants.

Akbar Davoodi also attended the conference and gave the talk Rule Inference and Maximal Common Subgraph in Chemical Reaction Networks.

The conference also included an 8 km bike ride up a mountain, an excursion to the ski-jumping venue Nordic Center Planica and a bike ride to Italy!

Simon Erfurth gave his first conference talk at the Joint Computation+Journalism Symposium and European Data & Computational Journalism Conference at ETH in Zürich. The title of the contribution was Adding Quotable Signatures to the Transparency Repertoire in Data Journalism, representing joint work between Simon and Marília Gehrke, now at the University of Groningen. As someone educated in pure math, attending and interacting with people in such an inter-disciplinary environment is an interesting experience, Simon says.

Anders Yeo and Jørgen Bang-Jensen were invited speakers at the Fifth ANR Digraph Meeting in Sete, France, between May 30 and June 2.

Jørgen gave the talk Open problems on directed graphs and Anders gave the talk Directed max-cut and some generalizations.

Not only was the workshop very stimulating academically, but it also included doing math on the beach!

During the month of May, Joan Boyar and Kim Skak Larsen visited the Department of Computer Science at the University of Toronto. While there, they both gave talks on some of their recent work on online algorithms with predictions, dealing with scheduling and paging, to be presented at WADS and ICML this summer. At the University of Toronto, they worked with Faith Ellen and Allan Borodin. In addition, Shahin Kamali came in from York University and Denis Pankratov came in from Concordia University to collaborate on new projects. It will be a challenge to find the time to make progress on the many new research projects when teaching starts!

ARCO, an acronym for Algorithmic Research Cooperation around Øresund, is a network for promoting collaboration in research within algorithms around the Øresund Region. This time, the ARCO meeting was held at KU and attended by Magnus Berg, Joan Boyar, Lene Favrholdt, and Kim Skak Larsen. Magnus gave his first talk as a Ph.D. student on Online Minimum Spanning Trees with Weight Predictions, a result which is also to be presented at the 18th International Algorithms and Data Structures Symposium (WADS). His presentation generated a lot of interest, the most follow-up questions of any of the presentations, and many of our colleagues complimented Magnus afterwards for his nice talk.

Kevin Schewior attended the Dagstuhl Seminar on Scheduling, organized by Nicole Megow (Bremen), Benjamin Moseley (CMU), David Shmoys (Cornell), Ola Svensson (EPFL), and Sergei Vassilvitskii (Google). About 50 researchers participated, among them a lot of big names from the scheduling community. This edition of the seminar series had a special focus on beyond-the-worst-case algorithm design and approaches that incorporate learning. Kevin gave a short talk on Evaluating Stochastic Score functions.