2020/02/21 by Visakan Balakumar, Balakumar, Visakan, Elizabeth Winstanley +1
Physics and Astronomy · #Cosmology and Gravitation Theories #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #High Energy Physics - Theory (hep-th) #Noncommutative and Quantum Gravity Theories #Quantum Electrodynamics and Casimir Effect
paper · pdf · doi:10.48550/arxiv.2002.09448
openalex publication_date 2020/02/21 · openalex created_date 2022/07/26 · openalex updated_date 2026/07/28
The Hadamard parametrix is a representation of the short-distance singularity\nstructure of the Feynman Green's function for a quantum field on a curved\nspace-time background. Subtracting these divergent terms regularizes the\nFeynman Green's function and enables the computation of renormalized\nexpectation values of observables. We study the Hadamard parametrix for a\ncharged, massive, complex scalar field in five space-time dimensions. Even in\nMinkowski space-time, it is not possible to write the Feynman Green's function\nfor a charged scalar field exactly in closed form. We therefore present\ncovariant Taylor series expansions for the biscalars arising in the Hadamard\nparametrix. On a general space-time background, we explicitly state the\nexpansion coefficients up to the order required for the computation of the\nrenormalized scalar field current. These coefficients become increasingly\nlengthy as the order of the expansion increases, so we give the higher-order\nterms required for the calculation of the renormalized stress-energy tensor in\nMinkowski space-time only.\n