# 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-StG 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 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..

## Contact

- Oliver Schlotterer
- oliver.schlotterer@physics.uu.se
- Department of Physics and Astronomy
- Uppsala University
- Box 516
- SE-75120 Uppsala
- Sweden