We are delighted to announce that Peter Kiss, a PhD student in the Theory and Foundations Research Division, has received the best student paper award at European Symposium on Algorithms (ESA) 2023, for his joint work with Joakim Bilkstad for the paper: "Incremental (1-eps)-approximate dynamic matching in O(poly(1/eps)) update time". The paper considers the problem of maintaining a large matching in a graph that is undergoing a sequence of edge insertions. They present an algorithm for this fundamental problem in dynamic graph algorithms, which has near-optimal approximation ratio and an update time that does not grow at all with the size of the input and is also polynomial in 1/\eps (the error parameter). In addition, their approach is simpler than previous algorithms on the same problem that achieved weaker guarantees.

Five papers from the Theory and Foundations (FoCS) Research Group and the Centre for Discrete Mathematics and its Applications (DIMAP) have been accepted to the 64th IEEE Symposium on Foundations of Computer Science (FOCS 2023), the IEEE flagship conference in theoretical computer science that will be held on November 6 - 9, 2023 in Santa Cruz, California, USA:

• "Chasing positive bodies" by Sayan Bhattacharya, Niv Buchbinder, Roie Levin, and Thatchaphol Saranurak.
• "Dynamic (1+epsilon)-approximate matching size in truly sublinear update time" by Sayan Bhattacharya, Peter Kiss, and Thatchaphol Saranurak.
• "Polynomial-time pseudodeterministic construction of primes" by Lijie Chen, Zhenjian Lu, Igor C. Oliveira, Hanlin Ren, and Rahul Santhanam.
• "Approximating edit distance in the fully dynamic model" by Tomasz Kociumaka, Anish Mukherjee, and Barna Saha.
• "Traversing combinatorial 0/1-polytopes via optimization" by Arturo Merino and Torsten Mütze.

Henry Sinclair-Banks, a PhD student in the the Theory and Foundations (FoCS) Research Group and the Centre for Discrete Mathematics and its Applications (DIMAP), has won a Best Paper Award at ICALP 2023, the 50th EATCS International Colloquium on Automata, Languages and Programming. ICALP is the main conference and annual meeting of the European Association for Theoretical Computer Science (EATCS).

Henry's paper, co-authored with researchers from Germany and Poland: Marvin Künnemann, Filip Mazowiecki, Lia Schütze, and Karol Węgrzycki, addresses the coverability problem in vector addition systems (VASS), a well-known model of concurrent systems. Coverability is an algorithmic problem for the verification of "safety properties": whether the system always avoids a set of bad states. Henry and his co-authors determine how much time is required to solve this problem in the worst case. They develop an algorithm that improves upon the state of the art that has stood for forty years. They also prove that, in several settings, it is impossible to decide coverability substantially faster, unless there is also a faster algorithm for a classic problem such as Boolean satisfiability (SAT) and finding cycles of fixed length in graphs.

In total, 5 Warwick papers will appear at this year's ICALP:

• Michael Benedikt, Dmitry Chistikov, and Alessio Mansutti, "The complexity of Presburger arithmetic with power or powers",
• Sam Coy, Artur Czumaj, Peter Davies, and Gopinath Mishra, "Optimal (degree+1)-coloring in congested clique",
• Charilaos Efthymiou and Weiming Feng, "On the mixing time of Glauber dynamics for the hard-core and related models on G(n,d/n)",
• Marvin Künnemann, Filip Mazowiecki, Lia Schütze, Henry Sinclair-Banks, and Karol Węgrzycki, "Coverability in VASS revisited: Improving Rackoff's bound to obtain conditional optimality",
• Konstantinos Zampetakis and Charilaos Efthymiou, "Broadcasting with random matrices".

This July's ICALP will be the 50th edition of the conference.