Quantum particle creation by cosmic strings in de Sitter spacetime

This paper explores the phenomenon of particle creation associated with cosmic strings (CS) in de Sitter spacetime, a model that represents the Universe’s exponential expansion. We examine how the presence of CSs in a de Sitter background affects particle production, focusing on the roles of string tension and angular deficits. Utilizing the Klein–Gordon equation adapted to curved spacetime with CS defects, we derive solutions expressed through hypergeometric functions to describe particle states. Our findings highlight how string properties influence particle creation rates and energy distributions. By analyzing both point-like and linear potentials near the string, we determine exact solutions, investigate asymptotic behaviors, and calculate particle creation probabilities using Bogoliubov transformations.