Best Student Paper Award for Fabian Egidy at ICALP 2026 in London

At the 53rd International Colloquium on Automata, Languages, and Programming (ICALP 2026) in London, Fabian Egidy was awarded the Best Student Paper Award in Track A (Algorithms, Complexity, Games). His paper “Recursive Jump Operators and Optimal Proof Systems” addresses one of the central open questions in proof complexity: Do optimal proof systems exist, i.e., strategies that prove statements at least as efficiently as all other alternative strategies?

The paper investigates whether, in the event that such optimal proof systems do not exist, there is a procedure that can algorithmically construct a stronger proof system for any given one. For all currently known sets without an optimal proof system (such as EXP-complete sets), the paper demonstrates that such constructive improvement procedures do indeed exist. For the particularly interesting case concerning the set of all propositional tautologies, where the non-existence of optimal proof systems is itself a central open conjecture, the article demonstrates that such a relationship cannot be shown using "standard" (so-called relativizable) methods. By this, the result establishes a new proof barrier, as candidate procedures for resolving this question require non-relativizing techniques in order to prove themselves as constructive improvement procedures.