My research focuses on the theory of strong interactions in high-energy particle collisions, combining perturbative QCD, effective field theory, and collider phenomenology.

A key challenge in modern collider physics is to model complex multi-scale processes involving jets and hadrons, and extract information from them. My work develops new observables and theoretical frameworks that connect quantum field theory with experimental measurements at facilities such as the Large Hadron Collider (LHC).

Jets and jet substructure

Jets are collimated sprays of particles and appear in almost all analyses at the LHC as either signal or background. The excellent performance of the LHC detectors has made it possible to study the internal structure of jets, providing a direct probe of the dynamics of quarks and gluons produced in these collisions. My research studies the structure of jets, including the development of theoretical descriptions of jet substructure, correlations between particles in jets, and the interplay between perturbative predictions and non-perturbative effects.

Precision QCD and Effective Field Theory

Effective field theories such as Soft-Collinear Effective Theory (SCET) provide a systematic framework to describe complicated radiation patterns in high-energy collisions. My research develops factorization formulae and resummation techniques that allow precise predictions for collider observables. These observables include jet substructure, energy correlators, and cross sections involving a Higgs boson and jets. Precise predictions with controlled theoretical uncertainties improve comparisons between theory and experiment.

New Observables for Collider Physics

New observables can provide new insights or reveal aspects of QCD dynamics that are otherwise difficult to access. My work has introduced several new observables that have become important tools in collider physics. Examples include N-jettiness, which characterizes radiation patterns and has been extensively used in jet substructure, but also as a slicing variable in calculations at high perturbative order. A recent example is a new parametrization of higher-point energy correlators, which offers an exponential speed-up and makes it feasible to apply these observables to real collider data.

Parton Dynamics and Hadronic Structure

The quarks and gluons in colliding hadrons radiate before collisions, and I developed the concept of beam function to describe this. Similarly, understanding how quarks and gluons evolve into the particles observed in detectors requires detailed knowledge of parton dynamics and fragmentation. My research includes studies of transverse-momentum distributions in hadrons and multi-parton correlations. I pioneered the framework of track functions to describe measurements of track-based observables.

Selected work

Below are several representative developments from my research program:

• Beam functions and precision Higgs+jet predictions.
  Introduced beam functions (PRD 2010) to describe initial-state radiation at the LHC, enabling the first precision prediction of Higgs production with a jet veto (JHEP 2011). I recently applied this to obtain state-of-the-art predictions for Higgs plus one jet (JHEP 2025).

• N-jettiness.
  An event-shape observable that characterizes radiation patterns (PRL 2010) and is now widely used both for identifying boosted objects (N-subjettiness) and for high-precision collider calculations (N-jettiness slicing).

• Multi-differential resummation (SCET+).
  A framework for systematically resumming logarithms when e.g. several observables are measured simultaneously (JHEP 2015), allowing reliable predictions for correlated measurements.

• Track functions and energy correlators
  A framework for describing track-based observables (PRL 2013), enabling precision predictions for measurements using only charged particles. Recently extended to high precision (PRL 2022) and applied to energy correlators (arXiv 2025).

• New parametrizations of higher-point energy correlators.
  Enables an exponential speed-up in the evaluation of energy correlators (PRL 2025), making it, for example, possible to study small-x dynamics in jets using collider data (PLB 2025).

• Transverse-momentum slicing for processes with jets.
  A slicing method for higher-order calculations of jet processes based on transverse momentum, exceptionally simple for planar Born processes (PRL 2025).

A full list of my publications can be viewed on Inspire.

• SCET Workshop 2026, Korea Institute For Advanced Study (March 2-5, 2026).
• INFN Torino seminar (October 29, 2025).
• BNL High Energy Theory seminar (June 12, 2025).
• TUM/MPP collider seminar (May 27, 2025).
• Theory day, University of Groningen (April 11, 2025).
• SM@LHC 2025, Durham University (April 7-10, 2025).
• Fragmentation in the Collider Precision Era, University of Zurich (March 17-19, 2025).

I lead a research group in theoretical particle physics at the University of Amsterdam and Nikhef. Our work focuses on precision QCD, jet physics, and collider phenomenology.

• Johannes Michel (D-ITP fellow)
• Ankita Budhraja (Postdoc)
• Alessio Vorona (PhD student)

• Marie Curie Staff Exchange (2025-2028)
• SPARC (2019-2021)
• NWO Projectruimte (2018-2023)
• ERC Starting Grant (2016-2021)
• MISTI Global Seed Fund (2015-2016)
• Veni (Lisa Zeune, group member, 2015-2017)
• Marie Curie Fellowship (2013-2015)

Current courses:

• Advanced Quantum Physics (bachelor)
• Effective Field Theory (master)

• Deputy group leader, Nikhef theory (2025–)
• Chair, Faculty of Science Works Council, University of Amsterdam (2024–)
• Dutch representative to plenary ECFA (2024–)
• National contact for the Future Circular Collider (2023–)
• Organizer or convener of conferences and workshops in QCD and collider physics (e.g. SCET 2018, QCD@LHC 2023, NWO Physics focus session 2026)
• Editorial board member, Scientific Reports

I am an Associate Professor at the University of Amsterdam and deputy leader of the Nikhef theory group. I received my PhD from MIT in 2010 and subsequently held a postdoctoral position at the University of California, San Diego. In 2013 I joined Nikhef as a Marie Curie Fellow and the University of Amsterdam as an Assistant Professor, becoming an Associate Professor in 2018.

I collaborate with colleagues at several institutions, including MIT, DESY, Yale, Complutense Madrid, Los Alamos, the University of Vienna, and Peking University. My research has been supported by several competitive grants, including an ERC Starting Grant and NWO Projectruimte funding.

Outside of physics I enjoy running, reading, and spending time with my wife and children.