Research interests

While many experiments test the boundary of our current understanding of nature, two major cornerstones are the Large Hadron Collider (LHC) and the LIGO/VIRGO gravitational wave observatories. Although these experiments test rather different aspects of nature, their physics programs require the application of novel theoretical ideas and techniques to compute scattering amplitudes that are at the heart of my research interest for precision calculations in the presence of massive particles.

Thanks to the higher collision energy and luminosity, Run 3 of the LHC and its high-luminosity upgrade (HL-LHC) will provide numerous measurements with few-percent accuracy. To harness the full potential of these measurements to perform precision tests of the Standard Model and constrain possible physics beyond the Standard Model (BSM), theory predictions have to improve to meet the demanded accuracy. In general, this requires the computation of higher-order corrections in perturbation theory. While for many $2\to 1$ and $2\to 2$ scattering processes the computation of next-to-next-to-leading order (NNLO) corrections or even higher orders in QCD have been achieved, only few calculations for much-needed $2\to 3$ processes exist to date, due to the increased complexity of these scattering amplitudes. In addition, electroweak (EW) and mixed QCD-EW corrections become necessary for a large class of processes.

With the direct detection of gravitational waves emitted during the merger of a binary black hole system by the Advanced LIGO detectors the era of multi-messenger astronomy has begun. The detection of gravitational waves provides new complementary information to well established methods such as the detection of gamma rays and neutrinos from distant sources. Gravitational waves also allow to study entire new phenomena in astronomy and cosmology that are hard to explore with other approaches as for example collisions of black holes or neutron stars, supernovae and maybe even the early universe itself. However, for these studies the theory predictions for the gravitational wave signals have to be very precise.

My research interests range from the phenomenology of the Standard Model to more formal aspects of field theories and scattering amplitudes. They are in more detail as follows:

• Phenomenology of the top quark at the LHC and beyond
• NLO QCD and EW corrections for high-multiplicity processes
• Development of efficient and precise tools for the study of processes of high complexity
• The analytic structure of two-loop scattering amplitudes with massive particles
• Quantum effective field theories of gravity and their implications for classical observables