5 papers
CosmoAgent: AI Agent for Theoretical Cosmology
Stephon Alexander, Loukas Gouskos, Savvas M. Koushiappas +2
We present CosmoAgent, an agentic AI framework using large language models (LLMs) to search for dark-energy and modified-gravity models. We define a covariant grammar that allows L…
Autonomous Discovery of Particle Physics Theories from Experimental Data
Stephon Alexander, Benjamin Bradley, Loukas Gouskos +1
The search for physics beyond the Standard Model is hindered by a combinatorial explosion of possible theories. We introduce \textsc{Albert}, a neuro-symbolic artificial intelligen…
Parity-violating Dark Photon Halos
Stephon Alexander, Lawrence Edmond, Cooper Niu
We propose a mechanism for the generation of gravitationally bound dark photon halos during the matter-dominated era. Coupled to an ultralight axion field through a parity-violatin…
Perturbations in pseudo-Nambu-Goldstone Higgs Inflation
Stephon Alexander, Humberto Gilmer, Cooper Niu
Pseudo-Nambu-Goldstone (pNG) Higgs Inflation is a novel approach to relate the Higgs boson and its interaction with Electroweak gauge bosons with cosmic inflation, with the potenti…
Vacuum Amplification of Chiral Gravitational Waves and the Stochastic Gravitational Wave Background
Stephon Alexander, Heliudson Bernardo, Yiya Selina Li +1
We investigate cosmological vacuum amplification of gravitational waves in dynamical Chern-Simons gravity. We develop a comprehensive framework to compute graviton production induc…