Principal investigator: Athanasios Chatzistavrakidis
PI's Host institution: Ruđer Bošković Institute
Project duration: 01.10.2018 to 30.09.2022

Project Summary

Reconciling general relativity and quantum mechanics and understanding the quantum structure of spacetime is one of the major challenges for present day theoretical physics. Two prominent frameworks addressing this conundrum are string theory and noncommutative geometry. Recent advances provide evidence that the generic spacetime geometries experienced by closed strings are noncommutative and even nonassociative.

Within this project we aim at a deeper understanding of the geometry and the gravitational sector of string theory. In particular, we are going to study strings propagating in backgrounds with non-geometric fluxes, using mathematical tools such as noncommutative and nonassociative differential geometry, Courant algebroids, generalized and higher geometry. Our main goal is to provide a solid geometric basis for T- and U-duality-invariant theories, such as double field theory and exceptional field theories, elucidate the structure of string and membrane sigma models, construct models of gravity in the presence of general fluxes and brane sources and study their physical implications. A second goal is to investigate the geometric structure of non-relativistic gravity theories, which attract a lot of interest in recent years due to applications in diverse physical settings, ranging from holography and condensed matter physics to string theory.

We expect that the results of this project will have an impact in our understanding of the gravitational interaction, and will contribute to the long-term goal of elucidating the origin and the structure of the universe.


May 20, 2020: New paper by two of the project associates, arXiv:2005.09001

Due to the conditions created by the Covid-19 pandemic, the workshop New Developments in Quantum Gravity and String Theory, scheduled for this September in Corfu, will not take place and it is postponed for September 2021.

Physics and Geometry Seminars in Zagreb.


Eric A. Bergshoeff

University of Groningen, Netherlands

Larisa Jonke

RBI, Croatia

Richard J. Szabo

Heriot-Watt University, United Kingdom

Zoran Škoda

University of Zadar, Croatia


Thomas Strobl

Institute Camille Jordan, Lyon, France


Zoltán Kökényesi

RBI, Croatia

PhD Students

Georgios Karagiannis

RBI, Croatia

Grgur Šimunić

RBI, Croatia

List of publications

Non-Relativistic Supersymmetry on Curved Three-Manifolds

Eric Bergshoeff, Athanasios Chatzistavrakidis, Johannes Lahnsteiner, Luca Romano, Jan Rosseel

Graded Geometry and Tensor Gauge Theories

Athanasios Chatzistavrakidis, Georgios Karagiannis, Peter Schupp
To be published in the Proceedings of Science

L∞-Algebras of Einstein-Cartan-Palatini Gravity

Marija Dimitrijević Ćirić, Grigorios Giotopoulos, Voja Radovanović, Richard J. Szabo

On interpolations between Jordanian twists

Daniel Meljanac, Stjepan Meljanac, Zoran Škoda, Rina Štrajn

Relation between standard and exotic duals of differential forms

Athanasios Chatzistavrakidis, Georgios Karagiannis
Published in Phys.Rev. D100 (2019) no.12, 121902 (Rapid Communications Section)

A unified approach to standard and exotic dualizations through graded geometry

Athanasios Chatzistavrakidis, Georgios Karagiannis, Peter Schupp
Published in Commun. Math. Phys. (2020)

One parameter family of Jordanian twists

Daniel Meljanac, Stjepan Meljanac, Zoran Škoda, Rina Štrajn
Published in SIGMA 15 (2019) 082

The Algebroid Structure of Double Field Theory

Athanasios Chatzistavrakidis, Larisa Jonke, Fech Scen Khoo, Richard J. Szabo
Published in PoS CORFU2018 (2019) 132

Fluxes in Exceptional Field Theory and Threebrane Sigma-Models

Athanasios Chatzistavrakidis, Larisa Jonke, Dieter Lüst, Richard J. Szabo
Published in JHEP 1905 (2019) 055

Talks and Seminars

12 May 2020: Invited seminar at the Albert Einstein Institute, Potsdam, Germany (A. Chatzistavrakidis; given online).

19 Feb 2020: Invited talk at the Solvay Workshop on "Higher Spin Gauge Theories, Topological Field Theory and Deformation Quantization", Brussels, Belgium (L. Jonke).

20 Dec 2019: Invited talk at the Xmas Theoretical Physics Workshop , Athens, Greece (A. Chatzistavrakidis).

22 Nov 2019: Invited seminar at the Jacobs University Bremen, Germany (A. Chatzistavrakidis).

20 Nov 2019: Invited seminar at the Institute for Theoretical Physics, Leibniz University Hannover, Germany (A. Chatzistavrakidis).

15 Oct 2019: Invited seminar at the Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, Netherlands (A. Chatzistavrakidis).

11 Oct 2019: Poster presentation at the Humboldt Kolleg: Science and Education Challenges Facing Europe in the Next Decade, Zagreb, Croatia (G. Karagiannis).

10 Oct 2019: Invited seminar at the Institut de Physique des 2 Infinis de Lyon, France (A. Chatzistavrakidis).

10-16 Sep 2019: Talk at the conference on Recent Developments in Strings and Gravity, Corfu, Greece (G. Karagiannis).

25-31 Aug 2019: Talk and poster at the workshop Supersymmetries and Quantum Symmetries 2019, Yerevan, Armenia (A. Chatzistavrakidis and G. Karagiannis).

22 May 2019: Rudjer Boskovic Institute Colloquium, Zagreb (R. Szabo).

20-24 May 2019: Two talks at the Mini-Symposium on Physics and Geometry, Rudjer Boskovic Institute, Zagreb (R. Szabo and G. Karagiannis).

13 Apr 2019: Invited talk at Bayrischzell Workshop 2019 Quantum structure of space-time: Generalized geometry and symmetries, Bayrischzell, Germany (A. Chatzistavrakidis).

11-15 Feb 2019: Talk at the Quantum Spacetime '19 workshop, Bratislava, Slovakia (A. Chatzistavrakidis).

7-11 Jan 2019: Talk at the 8th Bangkok Workshop on High-Energy Theory, Chulalongkorn University, Thailand (A. Chatzistavrakidis).

7 Nov 2018: Invited colloquium: Models of Gravity Research & Training Group, Jacobs University Bremen, Germany (A. Chatzistavrakidis).


Other Research Visits (without talk)

1-7 Dec 2019: Albert Einstein Institute, Potsdam, Germany (A. Chatzistavrakidis & L. Jonke).

4-8 Feb 2019: CERN Winter School on Supergravity, Strings and Gauge Theory (G. Karagiannis).

21 Oct - 15 Dec 2018: Visit at LMU Munich (A. Chatzistavrakidis and L. Jonke).


Event Organization

13-19 Sep 2020: New Developments in Quantum Gravity and String Theory , Corfu, Greece (postponed for 2021)

10-18 Sep 2019: Workshop on Recent Developments in Strings and Gravity , Corfu, Greece.

20-25 May 2019: Mini-Symposium on Physics and Geometry, Rudjer Boskovic Institute, Zagreb.


Dissemination and Outreach

12 Sep 2019: Live Interview for Corfu TV (A. Chatzistavrakidis, jointly with D. Giataganas from NKU Athens) watch

17 Sep 2019: Live Interview for ERT Corfu Radio (A. Chatzistavrakidis, jointly with P. Anastasopoulos from Vienna U.)



Summer Semester 2019: Superstring Theory and Branes.
PhD Program in Physics, Faculty of Science, University of Zagreb


Athanasios Chatzistavrakidis

Phone: +385 1 456 1121
Ruđer Bošković Institute
Bijenička cesta 54
10000 Zagreb, Croatia