Oliver Schlotterer
Research Interests
My research is centered on the rich physical implications and mathematical structures of string scattering amplitudes. First, I am studying the point-particle limit and low-energy expansion of string amplitudes to reveal striking connections between gauge theories, gravity and effective field theories. Second, I am using string amplitudes as a mathematical laboratory for integration on Riemann surfaces of different genera. In this way, string theory greatly facilitates the construction and organization of iterated integrals and modular forms which find applications in particle physics and inspire new mathematical research in number theory and algebraic geometry.

ERC Synergy Grant project MaScAmp 2025-2030
Together with Ruth Britto (Trinity College Dublin), Francis Brown (University of Oxford) and Axel Kleinschmidt (MPI for gravitational physics), we were awarded an ERC Synergy Grant in fall 2024 for the project MaScAmp – Mathematics of Scattering Amplitudes. During the funding period spring 2025 to spring 2030, we will work in a multidisciplinary team involving a total of approx. 20 scientists at the four nodes in Dublin, Oxford, Potsdam and Uppsala.
MaScAmp proposes a new paradigm for fundamental interactions in physics in the form of a unified mathematical approach to scattering amplitudes. The project brings together a multidisciplinary team with expertise in pure mathematics and theoretical physics who will develop a set of novel and efficient algorithmic methods with applications in mathematics, particle physics and gravity.
Discoveries in many areas of fundamental physics depend upon a detailed understanding of the scattering of particles. Modern experiments, such as particle colliders and gravitational-wave detectors, demand high-precision theoretical computations to make new discoveries. These are deduced from physical models by a highly labour-intensive process relying on the calculation of scattering amplitudes, which assign probabilities to particle interactions. Despite a tremendous worldwide effort over many decades, the methods used to compute increasingly complex scattering amplitudes remain disparate and fragmented. The work of the PIs in distinct domains suggests unexpected symmetries and universal rules obeyed by scattering amplitudes in different-looking areas of physics. This calls for a radically new way of studying scattering amplitudes.
MaScAmp will create a unified framework for the calculation of general scattering amplitudes by building upon the latest research in mathematics, notably in algebraic geometry and number theory. As a result, MaScAmp will overcome longstanding computational bottlenecks, push the boundaries of numerous areas of theoretical physics, such as quantum field theory, gravity and string theory, and inspire new mathematical research. A widely applicable computer software implementation will enable physicists to make previously inaccessible predictions for present and future experiments. A project of MaScAmp's scope and ambition is only achievable by combining the unique expertise of the PIs in complementary areas of mathematics and physics.
ERC-Starting Grant Project Uniscamp 2019-2023
My research during the period January 2019 to December 2023 was funded through the ERC Starting Grant project UNISCAMP – The unity of scattering amplitudes: gauge theory, gravity, strings and number theory. During this 60-month funding period, up to 5 simultaneous team members produced a total of 45 research papers that can be found on INSPIRE HEP, including the following research highlights:
- the long-sought-for explicit construction of polylogarithm functions on Riemann surfaces of arbitrary genus in Constructing polylogarithms on higher-genus Riemann surfaces arXiv:2306.08644
- relating the modular graph forms in genus-one string amplitudes to F. Brown’s equivariant iterated Eisenstein integrals in the algebraic-geometry literature Modular graph forms from equivariant iterated Eisenstein integrals arXiv:2209.06772
- new synergies between conventional string theories and the more recent ambitwistor and chiral models, informing string interactions of infinitely many modes from field-theory methods
- understanding and exposing the double-copy structure of gravitational amplitudes through a fusion of string-theory, field-theory and Lie-algebra methods
Reviews
My group coauthored three White Papers within the Snowmass community planning exercise:
- Functions Beyond Multiple Polylogarithms for Precision Collider Physics, arXiv:2203.07088
- Snowmass White Paper: String Perturbation Theory, arXiv:2203.09099
- Snowmass White Paper: the Double Copy and its Applications, arXiv:2204.06547
Moreover, I recently published a comprehensive review together with C. Mafra, Tree-level amplitudes from the pure spinor superstring, Phys. Rept. 1020 (2023), arXiv:2210.14241. We review the supersymmetric computation of multiparticle tree-level amplitudes of massless superstring excitations as well as their interplay with the gravitational double copy and multiple zeta values.
Review Material that you cannot find on the arXiv
- The number theory of string amplitudes Pdf, 372 kB. (draft version of a proceedings article for the conference “Numbers and Physics”, ICMAT, Madrid, Spain, September 2014)
- One-loop string scattering amplitudes as iterated Eisenstein integrals Pdf, 1 MB. jointly written with Johannes Broedel (draft version of a proceedings article for the KMPB Conference “Elliptic Integrals, Elliptic Functions and Modular Forms in Quantum Field Theory”, DESY Zeuthen, Zeuthen, Germany, October 2017).
Teaching
I am teaching a doublet of master courses on string theory from fall 2023 to spring 2024, the lecture notes including homework problems can be found in the file String Theory I and II Pdf, 14 MB..
Moreover, you can find the notes of Max Guillen's extra lectures on Advanced Topics in String Theory (March 2021) Pdf, 418 kB..
Kontakt
- Oliver Schlotterer
- oliver.schlotterer@physics.uu.se
- Department of Physics and Astronomy
- Uppsala University
- Box 516
- SE-75120 Uppsala
- Sweden