Local momentum space and the vector field
Abstract
The local momentum space expansion for the real vector field is considered. Using Riemann normal coordinates we obtain an expansion of the Feynman Green function up to and including terms that are quadratic in the curvature. The results are valid for a nonminimal operator such as that arising from a general Feynmantype gauge fixing condition. The result is used to derive the first three terms in the asymptotic expansion for the coincidence limit of the heat kernel without taking the trace, thus obtaining the untraced heat kernel coefficients. The spacetime dimension is kept general before specializing to four dimensions for comparison with previously known results. As a further application we reexamine the anomalous trace of the stressenergymomentum tensor for the Maxwell field and comment on the gauge dependence.
 Publication:

Physical Review D
 Pub Date:
 August 2014
 DOI:
 10.1103/PhysRevD.90.044072
 arXiv:
 arXiv:1408.0636
 Bibcode:
 2014PhRvD..90d4072T
 Keywords:

 04.62.+v;
 11.10.z;
 11.15.q;
 Quantum field theory in curved spacetime;
 Field theory;
 Gauge field theories;
 High Energy Physics  Theory
 EPrint:
 doi:10.1103/PhysRevD.90.044072