this is a reminder for Martin Grohe's talk with the title "The Quest for a Logic Capturing PTIME" taking place today at 12:30 in the B-IT room 5053.2. Please find the details below
--- Abstract --- Problems that are hard to describe are hard to solve and vice versa." This claim may seem naive or just wrong at first sight, but it is the underlying idea of a deep and fruitful connection between the descriptive complexity and the computational complexity of computational problems. Here descriptive complexity refers to the “language resources” required to express a problem in a formal language, or logic whereas computational complexity refers to the computational resources needed to solve the problem.
There are logical characterisations of many common complexity classes such as NP or PSPACE, but the question of whether there is a logical characterisation of the class PTIME of polynomial time solvable problems remains open. It was first asked by Chandra and Harel (1982) in the context of database theory, and later in a slightly different form by Gurevich (1988) in the context of finite model theory.
In this talk, I will review the question and speak about negative as well as positive results spanning the last 40 years. ----------------
Part of the programme of the research training group UnRAVeL is a series of lectures on the topics of UnRAVeL’s research thrusts algorithms and complexity, verification, logic and languages, and their application scenarios. Each lecture is given by one of the researchers involved in UnRAVeL.
This years topic is "Biggest Milestones - Research at Its Peak", UnRAVeL professors will present the most important milestone of their respective research.
All interested doctoral researchers and master students are invited to attend the UnRAVeL lecture series 2023 and engage in discussions with researchers and doctoral students.
Next week, Christina Büsing is going to give a talk with the title "Robust Strategic Planning for Mobile Medical Units"
We are looking forward to seeing you at the lectures. Kind regards, Jan-Christoph for the organisation committee