Exploring the Dark Sector: From EFTs to Holography

• Grant number: 25/05571-3
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: October 01, 2025
• End date: June 30, 2029
• Field of knowledge: Physical Sciences and Mathematics - Physics - Elementary Particle Physics and Fields
• Principal Investigator: Chee Sheng Fong
• Grantee: Sergio Barbosa Junior
• Host Institution: Centro de Ciências Naturais e Humanas (CCNH). Universidade Federal do ABC (UFABC). Santo André , SP, Brazil

Abstract

This PhD research program aims to explore the concept of Dark Sector in a broad sense, employing innovative ideas and cutting-edge methods of theoretical physics. The three main lines of research are the following. (A) The student will merge the methods of Effective Field Theory (EFT) with the formalism of splitting functions to compute the fluxes of pairs of dark particles emitted from nucleons and electrons. This formalism opens the possibility of studying a number of diffractive and emission processes at the LHC and beyond. For example, the approach effectively turns the LHC into a dark particle collider --- analogous to well-known photon collisions.(B) The student will explore the possibility of dark matter to be made of a strongly-interacting plasma instead of weakly-coupled particles, via a recently-discovered five-dimensional holographic model. A variety of developments include the search for halo-like solutions and the study of dark matter decay as a bulk Hawking effect. Such developments are also useful at a purely theoretical level from the viewpoint of the fluid/gravity correspondence. (C) The student will study the trace anomaly produced by a strongly-coupled dark sector and its consequences for gravity. The student will revisit in details the trace-anomaly driven scenario of inflation, including holographic realizations, and develop its phenomenology.Secondary projects include to study the predictions of gravitational EFTs on black holes, and a deeper understanding of the macroscopic forces induced by a background of dark particles. A number of the above research lines are highly active and demand pressing advancements.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

BARBOSA, SERGIO; FICHET, SYLVAIN; DE SOUZA, LUCAS. On the black hole weak gravity conjecture and extremality in the strong-field regime. Journal of High Energy Physics, v. N/A, n. 10, p. 30-pg., 2025-10-16. (21/10128-0, 25/05571-3, 23/11293-0)