Effective Theories for Nonperturbative Physics 2026

Contribution List

1. Welcome and Icebreakers

24/08/2026, 10:00

2. Generalized symmetries and non-invertible naturalness (30'+15')

Seth Koren (Notre Dame U.)

24/08/2026, 11:15

3. Skyrme-Dilaton

Roman Zwicky (U. Edinburgh)

24/08/2026, 14:00

I will motivate that the sigma meson could be a dilaton through gravitational form factors, which serve as a test of the IR-conformal ward identities in the broken phase. Then review the Skyrme model and introduce the sigma as dilaton to the model. It will be tested against static nucleon properties and shown to improve predictions considerably.

4. One instanton, many consequences: Axion potentials and proton decay, beyond the Standard Model (30'+15')

Pablo Sesma (IFAE Barcelona)

25/08/2026, 10:00

19. Daisy Resummation Beyond Leading Order (30'+15')

Martin Münzenberg (JGU Mainz)

25/08/2026, 11:15

6. Metastable defects and gravitational waves (45'+15')

Alberto Mariotti (Vrije Universiteit Brussel)

25/08/2026, 14:00

I will introduce basics aspects of cosmic defects, how they arise in cosmological phase transitions, and their implications for cosmology and gravitational waves.
I will then revisit the case of metastable defects, both in axion models and in theories with symmetry-breaking patterns analogous to the electroweak sector of the Standard Model. Next, I will focus on metastable strings arising in...

18. Renormalisable four-fermion interactions in four dimensions (30'+15')

Charlie Cresswell-Hogg

26/08/2026, 10:00

Four-fermion interactions are important in many areas of particle physics, from effective descriptions of weak interactions and QCD to parametrisations of new physics in frameworks such as SMEFT. In this talk I demonstrate that four-fermion interactions may develop strongly coupled UV fixed points in four dimensional QFTs, becoming non-perturbatively renormalisable, and UV completing...

22. Non-adiabatic sphaleron biasing and Baryogenesis (30'+15')

Miguel Vanvlasselaer (U. Barcelona)

26/08/2026, 11:15

9. Renormalizing the Nonrenormalizable in Perturbation Theory (45'+15')

Litim Daniel

26/08/2026, 14:00

24. Effective methods for bubble nucleation in cosmological phase transitions (30'+15')

Maciej Kierkla

26/08/2026, 15:30

I will present an overview of the calculation of the thermal bubble nucleation rate in the context of cosmological phase transitions (PT). Focusing on the case of “SU(2)+Higgs” like theories, I will illustrate the calculation of the nucleation rate in the framework of high-temperature dimensional reduction. I will present next-to-leading order results and discuss the limitations of employing...

10. Dynamics of nucleation in first-order phase transitions (30'+15')

Andrey Shkerin (Perimeter Institute)

27/08/2026, 10:00

I will discuss dynamical effects during bubble nucleation in thermal first-order phase transitions. These effects arise due to lack of local thermal equilibrium and affect the parameters of the transition including the nucleation rate. I will present a general method of calculating the dynamical nucleation rate. I will also present results from real-time classical lattice simulations showing...

11. Thermal nucleation in perturbation theory (30'+15')

Joonas Hirvonen (Nottingham U.)

27/08/2026, 11:15

Cosmological first-order phase transitions may have generated a gravitational wave background detectable by LISA, offering a unique window into physics beyond the Standard Model. A crucial step in predicting this background is the reliable computation of bubble nucleation rates. In this talk, we overview the current state of perturbative calculations based on effective field theories and...

12. Some thoughts on field redefinitions and/or low energy potentials (45'+15')

Joerg Jaeckel (Heidelberg U.)

27/08/2026, 14:00

13. Higher Charge Monopoles and GUT Physics (30'+15')

Daniel Brennan (Birmingham U.)

27/08/2026, 15:30

5. Towards the exotic infrared phases of chiral gauge theories (30'+15')

Alvaro Pastor Gutierrez

28/08/2026, 10:00

The infrared structure of gauge theories with chiral fermions remains largely unexplored. In this talk I will discuss the Bars-Yankielowicz class using the functional renormalisation group, building on recent developments in gauge-fermion systems that provide clear criteria for confinement and dynamical symmetry breaking. I will show how two distinct phases arise: one exhibiting both...

14. Supercooling and Conformality in confining transitions (30'+15')

Gaurang Ramakant Kane

28/08/2026, 11:15

Understanding the dynamics of first-order thermal deconfinement–confinement transitions in strongly coupled gauge theories is an open problem that has been studied from various perspectives, including supersymmetry, holography, and explicit lattice computations—each approach revealing a different aspect of the transition. In addition to their theoretical interest, such transitions are also...

34. Week 2 Icebreakers

31/08/2026, 09:45

29. Self Consistent Thermal Resummation: A Case Study of the Phase Transition in 2HDM

Pedro Bittar (Perimeter Institute)

31/08/2026, 10:00

16. Dynamical evolution of the pressure on the bubble wall (30'+15')

Benoit Laurent (Perimeter Institute)

31/08/2026, 11:15

First-order cosmological phase transitions proceed through the nucleation and growth of bubbles of the new phase, and can be a leading source of gravitational waves, baryogenesis, and dark matter in the early Universe. A central question is what happens to a bubble immediately after it nucleates: does the wall settle into a slow, subsonic regime, or does it accelerate to ultra-relativistic...

17. Chiral Gauge Theory on a Computer (45'+15')

Markus Luty (UC Davis)

31/08/2026, 14:00

7. Extracting zero-damped modes using exact WKB (30'+15')

Nils Wagner (TU Munich)

01/09/2026, 10:00

Zero-damped quasinormal modes are a characteristic feature of near-extremal black holes and are expected to play an important role in their late-time ringdown. In this talk, I will give a pedagogical introduction to the exact WKB method and show how it can be used to study the zero-damped spectrum of near-extremal Reissner--Nordström black holes, highlighting recent developments that make this...

32. Another Brick in the Wall: Domain Wall Networks Beyond Z₂ (30'+15')

Dhruv Pasari (Durham University)

01/09/2026, 11:15

Domain walls beyond the textbook Z₂ kink have been studied analytically and through effective models, but seldom simulated directly on the lattice. We close that gap, evolving Z₃ and Z₄ wall networks with CosmoLattice. These networks are qualitatively richer than Z₂: walls come in distinct species, meet along junctions, and can transmute into one another rather than simply annihilating. To...

20. Bounding a dark sector ChiPT Lagrangian with unitarity (45'+15')

Mia West (KIT)

01/09/2026, 14:00

21. UV/IR Mixing Through the Lens of Tensor Networks (30'+15')

Steven Abel

02/09/2026, 10:00

8. Gravitational waves from critical dynamics (30'+15')

Oliver Gould (Nottingham U.)

02/09/2026, 11:15

23. Thermal partition function from the S-matrix reloaded (45'+15')

Joan Elias Miro (ICTP Trieste)

02/09/2026, 14:00

Over the past decade, S-matrix-based methods have undergone a remarkable resurgence as elegant and powerful tools for extracting physical information without relying on an underlying Lagrangian formulation. A central question is: given the exact S-matrix of a quantum field theory, what can we learn about its thermodynamic properties?
In this talk, I will review the Dashen–Ma–Bernstein...

15. Real-time tunneling calculations in the steadyon picture (30'+15')

Thomas Steingasser (IFT/CSIC, UAM)

03/09/2026, 10:00

Quantum tunnelling is conventionally formulated through Euclidean instantons, obscuring the role of physical time and complicating non-vacuum initial states. I will review the steadyon picture, in which infinitesimally regulated real-time path integrals are controlled by complex saddles whose projections recover familiar instantons. I will summarize its applications to finite-temperature...

25. Excited-Vacuum Decay from Large-Order Perturbation Theory (30'+15')

Yan Luo (DESY and USTC, Hefei)

03/09/2026, 11:15

26. Non-perturbative QFT on the twisted four-torus (45'+15')

Mohamed Anber (Durham)

03/09/2026, 14:00

I will review the old 't Hooft construction of fractional instantons on the twisted four-torus and its relation to the modern language of 1-form symmetry. Then, I will describe how this setup enables us to perform nonperturbative calculations in QFT. In particular, I will discuss how to compute the gaugino condensates in supersymmetric theories on the four-torus.

31. Nonlocal Effective Field Theory Approach to Thermal Photon Condensation in a Strongly Magnetized Vacuum (30'+15')

Selym Villalba-Chavez (HHU Düsseldorf)

04/09/2026, 10:00

35. Closing wods

Dr Felix Yu (JGU Mainz)

04/09/2026, 10:45

28. Infrared divergence cancellation, monopole-fermion scattering, x-ray edge spectra, and open quantum system (30'+15')

Soo-Jong Rey (Kwangwoon University)

30. SU(N) Confining Bubbles at Large N: Finite Theta effects and strongly coupled plasma hydrodynamics (30'+15')

Nicklas Ramberg (SISSA)

27. The fermion sign problem in Gauss law sectors of quantum link models with dynamical matter (30'+15')

Pallabi Dey (Saha Institute of Nuclear Physics, Kolkata, India)

33. Theoretical uncertainties in (H)EFT: Equations of Motion vs. Field Redefinitions (30'+15')

Shakeel Ur Rahaman (IPPP Durham)

Effective field theories rely on truncated expansions whose interpretation is intertwined with redundancies from field redefinitions. This interplay raises important questions about power counting and the consistent assignment of theoretical uncertainties associated with neglected higher-dimensional operators. In this talk, I use field redefinition invariance as a tool to assess truncation...