Thermalization at High Energies

Introduction

Thermalization of closed quantum systems is central to the modern understanding of matter, from ultracold to ultrahot. High-TheQ studies thermalization of quantum fields excited by nuclear collisions at RHIC and LHC to energy densities equivalent to trillions of Kelvins. In such extreme environments, hadrons melt and the equilibrium state is the quark-gluon plasma. Theoretical control over thermalization at high energies is crucially needed for understanding when and how this equilibrium phase emerges in the experiments.

Current Theoretical Paradigm

The current theoretical paradigm for thermalization in quantum chromodynamics is based on hydrodynamic and non-thermal attractors (fixed points). They are novel examples of universal dynamics of non-equilibrium quantum fields.

Idealized Settings

Both were found in idealized settings of nuclear collisions with a high degree of symmetries and in particular corners of a microscopic parameter space.

Goals of High-TheQ

The goal of High-TheQ is to understand thermalization in quantum field theory beyond these idealizations. The project aims to address the following questions:

1. Do hydrodynamic attractors appear for off-central nuclear collisions?
2. Is there a gravity dual to a non-thermal attractor?
3. Do non-thermal and hydrodynamic attractors have a common origin, such as spontaneous symmetry breaking?

Methodology

To answer these questions, High-TheQ will adopt an interdisciplinary methodology, including:

• Data-driven approaches
• Mathematics of transseries
• Higher-curvature gravity

Background

High-TheQ is firmly rooted in my long-term efforts on ab initio modeling of thermalization at strong coupling, pioneering the use of transseries in non-equilibrium dynamics of relativistic systems and introducing hydrodynamic attractors. This gives me a unique opportunity to decisively advance the field with High-TheQ.