Novel Phases of Matter at Strong Coupling from Black Holes in String Theory

• Grant number: 24/16864-9
• Support Opportunities: Research Grants - Visiting Researcher Grant - International
• Start date: January 01, 2026
• End date: September 24, 2026
• Field of knowledge: Physical Sciences and Mathematics - Physics - Elementary Particle Physics and Fields
• Principal Investigator: Horatiu Stefan Nastase
• Grantee: Horatiu Stefan Nastase
• Visiting researcher: Andres Fernando Anabalon Dupuy
• Visiting researcher institution: Universidad De Concepción/Udec, Chile
• Host Institution: Instituto de Física Teórica (IFT). Universidade Estadual Paulista (UNESP). Campus de São Paulo. São Paulo , SP, Brazil
• Associated research grant: 19/21281-4 - Gauge / gravity duality, AP.TEM

Abstract

This project intends to characterize and generalize a new kind of holographic phase transition recently found by us in (see [1]). It will allow us to provide a theoretical description of new phases of matter and study at the same time the intricate phase space of black holes and solitons in string theory. Indeed, nowadays it is widely acknowledged that the partition function of the large N, strongly coupled limit of N = 4, SU(N) super Yang-Mills, is equal to the partition function of the AdS5 × S5 compactification of type IIB supergravity. This opens the possibility to understand this Quantum Field Theory non-perturbatively, a problem otherwise impossible to tackle. In this setting, different thermal states in the field theory are associatedwith black holes, while confining states are associated with gravitational solitons. Hence, studying black holes and solitons with the right boundary conditions allows us to understand the different phases that the strongly coupledfield theory has. This is the main goal of the project: To provide a general characterization of the possible phase transitions that the thermal states of the quantum field theory can undergo by means of holography, through the study of the corresponding supergravity solutions. This is a very interesting theoretical endeavor in its own right.However, the fact that the Quark-Gluon plasma is going to be examined by many near-future experiments makes the project particularly exciting when the dual QFT is defined in Minkowski spacetime. In this setting, the issue of phase transitions has been much less explored. Indeed, the paradigmatic example of phase transitions in holography is the Hawking-Page phase transition, which is driven by the non-trivial geometry of the spacetime where the QFT lives, which instead of Minkowski is R × S3. Our project indeed focuses in the infinite volumelimit, something that has already provided us with the very interesting result of locating a third-order phase transition in the Quark-Gluon plasma when the temperature and the chemical potential are related as ¿c = 2¿Tc (see [1]). The analysis of the stability of the solutions, characterization of the fluctuations and its holographic interpretation will also be tackled in this project. We plan to assign various tasks to students, post-docs, and researchers who are interested in this subject, with the goal of completing this characterization within the nine-month duration of the project. Additionally, we aim to make this project accessible to the entire scientific community in the state of São Paulo. To achieve this, the visiting professor intends to deliver a series of four lectures, outlining the problem and the specific tasks required to address it. (AU)