Foundations of General-Relativistic Gauge Field Theory

Contributed Talks

20. A Journey through Higher-Derivative Models in Contemporary Field Theory

Ronaldo Thibes (Universidade Estadual do Sudoeste da Bahia)

Contributed Talks

Contributed Talk

With a initial motivation of treating point charge divergences in electrodynamics, higher-derivative (HD) models have come a long way in quantum in field theory passing through important challenges concerning their unitarity evolution and existence of propagating ghost fields. In modern physics, the relevance of HD models relies not only on abstract mathematical curiosities, but actually...

24. Classical gauge theories and gravity

Sebastian Brezina (Comenius University in Bratislava)

Contributed Talks

Contributed Talk

It belongs to folklore that electromagnetic, electroweak, and strong interactions are understood as gauge theories. In contrast, the situation regarding gravitational interaction is often considered more complex. Since the 1960s, this complexity has led to extensive research on the question: Can gravity be understood as a gauge theory?
In this talk, we explore a framework for...

19. From generalized principal connections to generalized Yang-Mills theories

Hartwig Winterroth (University of Torino)

Contributed Talks

Contributed Talk

In the framework of the fiber bundle approach to covariant Lagrangian field theories we investigate the notions of generalized principal bundle and generalized principal connection as introduced by Castrillón López and Rodríguez Abella (2023), aiming at the development of an instance of generalized mathematical gauge theories. We provide a characterization of Lie group fiber bundle connections...

23. Gauge-Invariant Renormalisation Group Flows

Paul Philip Sprenger (Institute for Theoretical Physics, Heidelberg University)

Contributed Talks

Contributed Talk

In this talk I give a brief introduction to the functional renormalisation group, a non-perturbative framework widely used to study gauge field theories. While this approach has been successfully applied to Yang–Mills theory and quantum gravity, standard implementations generally modify gauge invariance. This modification obscures the physical interpretation of results. I present a novel...

18. Gravity is gauge? A unification perspective

Priidik Gallagher (University of Tartu)

Contributed Talks

Contributed Talk

The question of the extent to which gravity is a gauge theory can prove to be surprisingly complicated, considering constraint classes, internal and external symmetries, spacetime tangent structure, and connection versus metric variables. Furthermore, unifying gravity with the rest of the interactions provides even more conundrum, but also an arena for theory development. The premise for...

27. Holographic thermal propagator from modularity

Katarina Trailović (Institute Jožef Stefan)

Contributed Talks

Contributed Talk

We revisit the low-temperature thermal propagator of a holographic conformal field theory in four spacetime dimensions by exploiting its connection to the Nekrasov–Shatashvili (NS) limit of the $\Omega$-deformed $\mathcal{N}=2$ supersymmetric $SU(2)$ Yang–Mills theory with $N_f=4$ hypermultiplets. In the regime of vanishing energy, the low-temperature expansion corresponds to a large adjoint...

29. Soft charges in 3D Maxwell theory at null infinity and horizons

Olivera Mišković (Pontificia Universidad Católica de Valparaíso, Chile)

Contributed Talks

Contributed Talk

Asymptotic symmetries at null boundaries often signal the presence of soft degrees of freedom and associated conserved charges. Here, these symmetries are studied in three-dimensional electromagnetism in two complementary contexts: null infinity of flat spacetime and the null boundary provided by the BTZ horizon. Both analyses lead to two sets of soft charges: the usual electric charge and an...

25. The autoparallel equations with non-metricity as Finsler geodesics

Lehel Csillag (Transilvania University Brasov)

Contributed Talks

Contributed Talk

Autoparallel curves in metric-affine geometries are generally non-variational and do not generally coincide with the Euler-Lagrange equations of any Lagrangian. For symmetric connections with vectorial nonmetricity, we show that the autoparallel equations can be realized as geodesics of a suitably chosen Finsler metric, reducing the problem of variationality to Finsler metrizability. By...

26. The Katz, Bičák and Lynden-Bell (KBL) regularization and its applications

Nelson Merino (Universidad Arturo Prat, Iquique, Chile)

Contributed Talks

Contributed Talk

The Katz boundary term provides a well-defined variational principle under Dirichlet boundary conditions and, when combined with a subtraction of the action evaluated on a background, known as the KBL regularization procedure, yields finite Noether charges and a finite on-shell action. This boundary term is constructed from the dynamical metric and the difference between the Christoffel...

30. Weyl-Invariant Equations from Gauge PDEs with Asymptotic Boundaries

Mikhail Markov (University of Mons)

Contributed Talks

Contributed Talk

I plan to discuss the applications of the gauge PDE approach to the study of the boundary structure of gauge fields on the conformal boundary of asymptotically AdS spaces.

The main result is the construction of an efficient calculus for the gauge PDE induced on the boundary, which allows one to systematically derive Weyl-invariant equations induced on the boundary. The so-called obstruction...