The field of nonperturbative physics has seen significant growth and increasing interest from groups with diverse perspectives, with notable impact on our understanding of quantum theories ranging from phenomenology to model-building as well as the Standard Model to beyond. This CERN-TH institute aims to grow this community (see the 2024 MITP workshop of the same name, MITP Scientific Program 2024) by building and fostering connections between these different groups seeking to characterize nonperturbative physics with effective descriptions. The current lack of new physics signals in its perturbative description combined with the intrinsic breakdown of perturbative expansions arising from their asymptotic nature has inspired the community collectively to tackle the questions of phenomenological predictions in nonperturbative regimes and connections in observables across the perturbative-nonperturbative transition.

We envision the thematic focus of talks and discussions to include:

• Perturbation theory at large quantum numbers
• Tunneling phenomena and false vacuum decay at zero and finite temperatures
• Hamiltonian truncation methods
• New techniques and insights for all-orders calculations (resurgence, semi-classics, lattice and discretization methods, supersymmetric deformations)
• Phenomenology of topological objects (sphalerons, instantons, axion strings, domain walls)
• Cross-cutting ideas to related directions, such as quantum computing, generalized global symmetries, etc.

The program will include morning plenary talks and free time in the afternoons for open discussions. The workshop will emphasize crosstalk between different approaches to understand nonperturbative phenomena, with the goal of inspiring new collaborations and uncovering new regimes to explore.