September 23 – 28 , 2018, Dagstuhl Seminar 18391

Algebraic Methods in Computational Complexity


Markus Bläser (Universität des Saarlandes, DE)
Valentine Kabanets (Simon Fraser University – Burnaby, CA)
Jacobo Torán (Universität Ulm, DE)
Christopher Umans (CalTech – Pasadena, US)

For support, please contact

Susanne Bach-Bernhard for administrative matters

Michael Gerke for scientific matters


Computational Complexity is concerned with the resources that are required for algorithms to detect properties of combinatorial objects and structures. It has often proven true that the best way to argue about these combinatorial objects is by establishing a connection (perhaps approximate) to a more well-behaved algebraic setting. Indeed, many of the deepest and most powerful results in Computational Complexity rely on algebraic proof techniques. The Razborov-Smolensky polynomial-approximation method for proving constant-depth circuit lower bounds, the PCP characterization of NP, and the Agrawal-Kayal-Saxena polynomial-time primality test are some of the most prominent examples.

The algebraic theme continues in some of the most exciting recent progress in computational complexity. There have been significant recent advances in algebraic circuit lower bounds, and the so-called “chasm at depth 4” suggests that the restricted models now being considered are not so far from ones that would lead to a general result. There have been similar successes concerning the related problems of polynomial identity testing and circuit reconstruction in the algebraic model (and these are tied to central questions regarding the power of randomness in computation).

Another surprising connection is that the algebraic techniques invented to show lower bounds now prove useful to develop efficient algorithms. For example, Williams showed how to use the polynomial method to obtain faster all-pair-shortest-path algorithms.

Furthermore, the program of geometric complexity initiated by Mulmuley tries to use methods from algebraic geometry and representation theory to resolve algebraic analogues of the P versus NP question.

These new directions will be in the focus of this Dagstuhl Seminar and reflect the developments in the field since the previous Seminar 14391.

The seminar aims to capitalize on recent progress and bring together researchers who are using a diverse array of algebraic methods in a variety of settings. Researchers in these areas are relying on ever more sophisticated and specialized mathematics and this seminar will play an important role in educating a diverse community about the latest new techniques, spurring further progress.

  Creative Commons BY 3.0 DE
  Markus Bläser, Valentine Kabanets, Jacobo Torán, and Christopher Umans

Dagstuhl Seminar Series


  • Data Structures / Algorithms / Complexity


  • Computational complexity
  • Algebra
  • (de)randomization
  • Circuits
  • Coding

Book exhibition

Books from the participants of the current Seminar 

Book exhibition in the library, ground floor, during the seminar week.


In the series Dagstuhl Reports each Dagstuhl Seminar and Dagstuhl Perspectives Workshop is documented. The seminar organizers, in cooperation with the collector, prepare a report that includes contributions from the participants' talks together with a summary of the seminar.


Download overview leaflet (PDF).


Furthermore, a comprehensive peer-reviewed collection of research papers can be published in the series Dagstuhl Follow-Ups.

Dagstuhl's Impact

Please inform us when a publication was published as a result from your seminar. These publications are listed in the category Dagstuhl's Impact and are presented on a special shelf on the ground floor of the library.

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