Elite Network: Interaction between Light and Matter

Interaction between Light and Matter

The central topic of this research group is the interaction between light and matter, more precisely electrodynamic fields and charged elementary particles. Apart from gravitation, this interaction governs the biggest part of our daily experiences. We owe to it everything we see and feel. It has long been the subject of study with traditional treaties. Yet in many aspects its foundational understanding still lies on the frontier of human knowledge, rendering its study at the same time traditional and novel.

The Junior Research Group at a glance

Place of researchLMU Munich
AssociationElite Graduate Program “Theoretical and Mathematical Physics”
Project duration2014 to 2019
Group leaderDr. Dirk-André Deckert
Contact the group leader
Further informationWebsite of “Interaction between Light and Matter”

Fundamental Structure and Processes of Matter

In its modern form, known as "quantum elec­tro­dynamics", the elec­tro­dynamic theory has led to many crucial predictions which have been verified with remarkable accuracy in particle collider experiments such as the CERN. In these experiments elementary par­ti­cles clash violently into each other, interact shortly, and scatter apart. The analysis of recorded scattering cross sections then gives insights into the fun­da­men­tal structure and processes of matter.

Description of Radiation Reaction and Pair Creation

Despite its success, however, the mathematical foundation of the theory of electro­dynamics is plagued by ill-defined equations of motion which generate infinities that cause any straight-forward computation of measurands to fail. To extract predictions, physicists and mathe­ma­ti­cians developed formal computation recipes known as "perturbative renormalization theory".


Though a mathematical rigorous understanding of these methods is lacking, they seem to work well in regimes where, e.g., colliding particles do not have much time to interact before they scatter apart. In other regimes where, e.g., charged particles are subject to ultra-strong laser fields for extended periods of time, theory as well as experiment indicate that such conventional methods may fail in producing satis­factory predictions.

Portrait photo: Dr. Dirk – André Deckert

Judging from my experience abroad and my supervision within “Theoretical and Mathematical Physics”, the Elite Network a provides a top notch line of funding programs that compete internationally - one of the reasons I returned to Germany.

Dr. Dirk-André Deckert

In the next two decades, however, a new generation of experiments will explore nature far beyond such mere scattering situations. This is due to recent advances in laser technology, a tech­nology that will allow to probe electrodynamic phenomena in much more controlled en­vi­ron­ments and may shrink experimental setups like the CERN with a 26 ki­lo­meters circumference to the size of laboratory tables. For planning, pre­dic­tion, and analysis of such experiments, new mathematically rigorous so-called “non-perturbative” methods have to be developed. This, beside foundational questions of quantum electro­dynamics, is our primary objective.

The main research topics encompass the controlled creation of a cascade of matter-anti­matter (electron-positron) pairs out of the vacuum in view of planned experiments within the European project “Extreme Light Infrastructure” as well as the accurate pre­dic­tion of radiation-induced friction of accelerated charges which is a crucial ingredient for the near-future wake field accelerator technology.

Beyond the value of the fundamental understanding of nature, this field of research has a far outreach. It has provided the foundations and repeatedly re­vo­lu­tionized the de­ve­lop­ment of high-technology in clinical diagnostics, nuclear pharmacology, and oncology.

The international junior research group cooperates with the Elite Graduate Program “Theoretical and Mathematical Physics” of the Ludwig-Maximilians-University Munich.

Further cooperations

ETH ZurichZurich, Switzerland
Griffith UniversityBrisbane, Australia
University of CaliforniaDavis, USA
Universität Tor VergataRome, Italy
Universität TriestTrieste, Italy