Office: 202, 2a| Phone: +49 (0)40 8998 2412| Email: georgios.papathanasiou[at]desy.de

### Welcome

I am a theoretical physicist working at the Deutsches Elektronen-Synchrotron since April 2017. Before coming here, I held postdoctoral positions at SLAC, LAPTh Annecy (also visiting scientist at CERN), and the University of Florida. I originally got my PhD from Brown University in 2011.

More on my academic path can be found in my CV.

### Research

My research focuses on Quantum Field Theory, String Theory, the relation between the two, and their fruitful interplay with contemporary mathematics. Performing explicit computations of important physical quantities at weak and strong coupling, and exploring their results to establish and exploit connections with new mathematical structures, lies at the core of my approach.

In particular, I have achieved significant contributions in the study of quantities such as anomalous dimensions, string state energies, Wilson loops, and more recently scattering amplitudes, which form a bridge between theory and experiment. To this end, I have employed and continue to further develop a wealth of complementary methods, ranging from gauge/string duality and integrability, to lattice discretization, and the exploitation of the expected analytic behavior of the relevant physical quantity. The latter also enjoys certain remarkable connections to tropical geometry and cluster algebras.

Ultimately, my research aims towards an all-loop solution of an interacting, four-dimensional gauge theory, for the simplest example of planar, maximally supersymmetric Yang-Mills theory. It is very likely that along the way, the new insights gained and computational tools built, will also find applications to the real world of elementary particles, and their interactions.

### Selected Publications

Full list available on INSPIRE.

- "Cluster algebras for Feynman integrals", with D.Chicherin, J.M.Henn, Phys.Rev.Lett. 126 (2021) 9, 091603, arXiv:2012.12285 [hep-th].
- "The Steinmann Cluster Bootstrap for N=4 Super Yang-Mills Amplitudes", with S.Caron-Huot, L.Dixon, J.Drummond, F.Dulat, J.Foster, O.Gurdogan, M.Hippel and A.McLeod, CORFU2019 Proceedings, arXiv:2005.06735 [hep-th].
- "The Origin of the Six-Gluon Amplitude in Planar N=4 SYM", with B.Basso and L.J.Dixon, Phys.Rev.Lett. 124 (2020) 16, 161603, arXiv:2001.05460 [hep-th].
- "How tropical are seven- and eight-particle amplitudes?", with N.Henke, JHEP 08 (2020) 005, arXiv:1912.08254 [hep-th].
- "All-order amplitudes at any multiplicity in the multi-Regge limit", with V.Del Duca, S.Druc, J.Drummond, C.Duhr, F.Dulat, R.Marzucca and B.Verbeek, Phys.Rev.Lett. 124 (2020) 16, 161602, arXiv:1912.00188 [hep-th].
- "The Cosmic Galois Group and Extended Steinmann Relations for Planar N=4 SYM Amplitudes", with S.Caron-Huot, L.Dixon, F.Dulat, M.Hippel, and A.McLeod, JHEP 1909 (2019) 061, arXiv:1906.07116 [hep-th].
- "Heptagons from the Steinmann Cluster Bootstrap", with L.J.Dixon, J.Drummond, T.Harrington, A.J.McLeod, and M.Spradlin, JHEP 1702, 137 (2017) , arXiv:1612.08976 [hep-th].
- "Multi-Regge kinematics and the moduli space of Riemann spheres with marked points", with V.Del Duca, S.Druc, J.Drummond, C.Duhr, F.Dulat, R.Marzucca and B.Verbeek, JHEP 1608, 152 (2016), arXiv:1606.08807 [hep-th].
- "Hexagon OPE Resummation and Multi-Regge Kinematics", with J.M.Drummond, JHEP 1602,185 (2016), arXiv:1507.08982 [hep-th].
- "A Symbol of Uniqueness: The Cluster Bootstrap for the 3-Loop MHV Heptagon", with J.M.Drummond and M.Spradlin, JHEP 1503, 072 (2015), arXiv:1412.3763.
- "Hexagon Wilson Loop OPE and Harmonic Polylogarithms", JHEP 1311, 150 (2013), arXiv:1310.5735.

### Selected Presentations

- Integrable limits of scattering amplitudes: Slides, Video
- All-order amplitudes at any multiplicity in the multi-Regge limit: Slides, Video
- How tropical are scattering amplitudes? Video
- The Steinmann Cluster Bootstrap for N = 4 SYM Amplitudes: Slides, Video
- N=4 Super Yang-Mills Amplitudes and Integrability: Slides
- String Self-energies on the Lightcone Worldsheet Lattice: Slides
- Dicretizing String Theory: Slides
- Evaluating the Hexagon Wilson Loop OPE: Mathematica Presentation
- Giant Magnons on Symmetric Spaces: Slides Poster
- Two-loop Spectroscopy of Short ABJM Operators: Slides
- The Morphology of N=6 Chern-Simons Theory: Poster
- Semiclassical Quantization of the Giant Magnon: Slides

### Selected Awards & Grants

- Principal Investigator in postdoctoral grant funded by the Helmholz Association and the Office of China Postdoctoral Council, 2020-2022
- Elected Key Researcher of the Quantum Universe Excellence Cluster at the University of Hamburg and DESY, January 2020
- Member of the EU Innovative Training Network "Scattering Amplitudes: From Geometry to Experiment" (SAGEX), 2018-2022
- Dissertation Fellowship at Brown University, 2009-2010
- Award for Excellence as a Graduate Teaching Assistant at Brown University, 2008
- Scholarship from Ioannis Varykas Foundation for undergraduate studies at the University of Athens, 1999-2003

### Teaching

I greatly enjoy transferring knowledge, and during my PhD I had the chance to be a teaching assistant for many undergraduate courses ranging from Modern Physics to Classical Mechanics or Electromagnetism. The experience that shaped my teaching philosophy was my collaboration with Professor Leon Cooper on the design and teaching of an interdisciplinary course exploring the relation of physics and art.

My interest in teaching has also led me to attend the Teaching Certificate I & III programmes at Brown University's Sheridan Center for Teaching & Learning. After my PhD, I had the opportunity to give a specialized course on Amplitudes & Symbols, and also give guest lectures in graduate Quantum Mechanics I, Quantum Field Theory II and Introduction to Supersymmetry and Supergravity. More recently, I have taught part of the 2018 String Steilkurs graduate-level intensive course at DESY, as well as the Spring 2020 MSc course Quantum Field Theory II at the University of Hamburg, receiving excellent evaluations.