Kyushu IAS-iTHEMS conference: Non-perturbative methods in QFT
- Date
- March 10 (Mon) at 9:42 - March 14 (Fri) at 17:00, 2025 (JST)
- Venue
- Kyushu University Ito Campus, Inamori Hall
- Language
- English
- Host
- Masazumi Honda
The most commonly used approach in the study of QFT is perturbation theory. Indeed, we have succeeded in extracting various physical quantities from perturbative (asymptotic) expansions. However, some physical phenomena cannot be captured through perturbative analyses alone. How can we extract these non-perturbative effects?
In QFTs with conformal symmetry (i.e., CFTs), correlation functions can be computed using a method called the conformal bootstrap. This non-perturbative method differs entirely from the usual correlation function analysis methods of QFT, as it does not even assume the existence of a Lagrangian. Through the use of the conformal bootstrap, we have actually made significant progress in the non-perturbative understanding of CFTs.
Furthermore, according to the holographic principle, CFTs provide a non-perturbative formulation of QFTs with gravity (i.e., quantum gravity). By applying the holographic principle to various non-perturbative results from CFTs, such as those obtained from the conformal bootstrap, we have made remarkable advances in understanding the non-perturbative aspects of quantum gravity. Conversely, the holographic principle is also used to understand properties of QFTs that are difficult to analyze perturbatively, through gravity.
Another frequently used approach for understanding non-perturbative aspects involves the use of interfaces. Although there are various ways to apply interfaces, some examples include:
- Symmetry,
- Non-local probes (such as Wilson lines or entanglement entropy),
- RG interfaces (used as a tool to understand the UV/IR map).
Regarding the first point, the relation “symmetry ⇒ topological interface” is well-known, but in general, topological interfaces do not have a group structure, so the reverse does not hold. However, it has recently been recognized that even topological interfaces without group structures can be as powerful as symmetry (sometimes called "generalized symmetry"), and there has been a dramatic development in understanding the properties and applications of topological interfaces in recent years.
The purpose of this conference is to bring together experts who have contributed to the recent advancements in non-perturbative methods of QFTs, to generate new collaboration research from the multifaceted perspective.
In this conference, we plan to cover the following topics, though we welcome any experts on non-perturbative analysis methods beyond these:
- Bootstrap,
- Non-local operator,
- Holography (understanding non-perturbative aspects from one side to the other).
This is a closed event for scientists. Non-scientists are not allowed to attend. If you are not a member or related person and would like to attend, please contact us using the inquiry form. Please note that the event organizer or speaker must authorize your request to attend.