Oliver Schlotterer

Oliver Schlotterer phone: +46(0)18 471 xxxx 
RESEARCH Interests
My research is centered on the rich interplay between string theories, unifying structures in perturbative field theories and modern topics in number theory. More specifically, I am studying scattering amplitudes in string and field theories as a smoking gun for striking connections between gauge theories, gravity and effective field theories. This includes interdisciplinary research on the intriguing mathematical structures of multiple zeta values, polylogarithms and their generalizations to higher genus which arise in both string amplitudes and Feynman integrals. My work has pinpointed stringtheory origins of doublecopy structures in perturbative gravity, a variety of surprising fieldtheory structures in string amplitudes and the first instances of elliptic multiple zeta values in physics.
ERCStG project UNISCAMP – The unity of scattering amplitudes: gauge theory, gravity, strings and number theory
Scattering amplitudes are central observables in quantum field theory and provide essential information about the quantum consistency of perturbative gravity. Precise control of the physical and mathematical properties of scattering amplitudes holds the key to longstanding questions on fundamental interactions and the structure of space and time. As a concrete leap in this direction, UNISCAMP addresses predictions in gauge theories, gravity and effective theories through
 the efficient computation and compact representation of scattering amplitudes and,
 decoding their hidden structures & symmetries and their rich web of connections.
Stringtheory methods will complement conventional approaches to scattering amplitudes, and UNISCAMP will combine the insights from
 the pointparticle limit of superstrings & heterotic strings and,
 the recent ambitwistor strings which directly compute fieldtheory amplitudes.
Both of them naturally incorporate the doublecopy relation between gaugetheory & gravity amplitudes and extend the framework to effective field theories describing pions and other lowenergy states. It is a primary goal of UNISCAMP to pinpoint the unifying principles connecting a wide range of field and string theories.
Moreover, field and stringtheory amplitudes exhibit an intriguing mathematical structure: Their Feynman and modulispace integrals yield special functions such as polylogarithms which became a vibrant common theme of highenergy physics and number theory. An interdisciplinary goal of UNISCAMP is to
 investigate the lowenergy expansion of multiloop string amplitudes and,
 extract an organizing scheme for iterated integrals on highergenus Riemann surfaces.
Review material that you cannot find on the arXiv
 The number theory of string amplitudes (draft version of a proceedings article for the conference “Numbers and Physics”, ICMAT, Madrid, Spain, September 2014)

Oneloop string scattering amplitudes as iterated Eisenstein integrals 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 plan to teach a stringtheory course starting from September 2019.
Recent publications

OneLoop String Scattering Amplitudes as Iterated Eisenstein Integrals
20190520
by: Broedel, Johannes (Humboldt U., Berlin) et al.
Abstract:
In these proceedings we review and expand on the recent appearance of iterated integrals on an elliptic curve in string perturbation theory. We represent the lowenergy expansion of oneloop openstring amplitudes at multiplicity four and five as iterated integrals over holomorphic Eisenstein series. The framework of elliptic multiple zeta values serves as a link between the punctured Riemann surfaces encoding string interactions and the iterated Eisenstein integrals in the final results. In the fivepoint setup, the treatment of kinematic poles is discussed explicitly.... 
Towards the npoint oneloop superstring amplitude III: Oneloop correlators and their doublecopy structure
20181231arXiv:1812.10971
by: Mafra, Carlos R. (Southampton U.) et al.
Abstract:
In this final part of a series of three papers, we will assemble supersymmetric expressions for oneloop correlators in purespinor superspace that are BRST invariant, local, and single valued. A key driving force in this construction is the generalization of a so far unnoticed property at treelevel; the correlators have the symmetry structure akin to {\it Lie polynomials}. Oneloop correlators up to seven points are presented in a variety of representations manifesting different subsets of their defining properties. These expressions are related via identities obeyed by the kinematic superfields and worldsheet functions spelled out in the first two parts of this series and... 
Towards the npoint oneloop superstring amplitude I: Pure spinors and superfield kinematics
20181231arXiv:1812.10969
by: Mafra, Carlos R. (Southampton U.) et al.
Abstract:
This is the first installment of a series of three papers in which we describe a method to determine higherpoint correlation functions in oneloop opensuperstring amplitudes from first principles. In this first part, we exploit the synergy between the cohomological features of purespinor superspace and the purespinor zeromode integration rules of the oneloop amplitude prescription. This leads to the study of a rich variety of multiparticle superfields which are local, have covariant BRST variations, and are compatible with the particularities of the purespinor amplitude prescription. Several objects related to these superfields, such as their nonlocal counterparts an... 
Towards the npoint oneloop superstring amplitude II: Worldsheet functions and their duality to kinematics
20181231arXiv:1812.10970
by: Mafra, Carlos R. (Southampton U.) et al.
Abstract:
This is the second installment of a series of three papers in which we describe a method to determine higherpoint correlation functions in oneloop opensuperstring amplitudes from first principles. In this second part, we study worldsheet functions defined on a genusone surface built from the coefficient functions of the KroneckerEinsenstein series. We construct two classes of worldsheet functions whose properties lead to several simplifying features within our description of oneloop correlators with the purespinor formalism. The first class is described by functions with prescribed monodromies, whose characteristic shufflesymmetry property leads to a Liepolynomial ... 
Heteroticstring amplitudes at one loop: modular graph forms and relations to open strings
20181107arXiv:1811.02548
JHEP 1901 (2019) 052
by: Gerken, Jan E. (Potsdam, Max Planck Inst.) et al.
Abstract:
We investigate oneloop fourpoint scattering of nonabelian gauge bosons in heterotic string theory and identify new connections with the corresponding openstring amplitude. In the lowenergy expansion of the heteroticstring amplitude, the integrals over torus punctures are systematically evaluated in terms of modular graph forms, certain nonholomorphic modular forms. For a specific torus integral, the modular graph forms in the lowenergy expansion are related to the elliptic multiple zeta values from the analogous openstring integrations over cylinder boundaries. The detailed correspondence between these modular graph forms and ellip...